STATE STANDARD

USSR UNION

TECHNICAL CONDITIONS

GOST 6637-80

Official publication

PUBLISHING HOUSE OF STANDARDS Moscow

UDC 621.914.6:006.354 Group G2H

STATE STANDARD OF THE USSR UNION

Finishing hob cutters for splined shafts with involute profile

Specifications

Finishing involute spline hobs. Specifications

Date of introduction 01/01/82

This standard applies to worm-type finishing cutters for processing gear (spline) shafts with an involute profile in accordance with GOST 6033-80 and GOST 6033-51.

The requirements of the standard regarding section. 1, 2, 4, 5 and clause 3.2 are mandatory, other requirements of this standard are recommended.

1. TYPES AND MAIN DIMENSIONS

1.1. The cutters must be made of the following types:

1 -- for processing shafts with a flat cavity;

2 - for processing shafts with a rounded cavity.

1.2. The cutters must be made right-handed with left-handed helical grooves of accuracy classes A, B and C.

1.3. The main dimensions of section cutters must correspond to those indicated in the drawing and in the table. 1.

Example of symbol designation for a milling cutter with module /Ppo=5.0 mm, accuracy class A, type 1:

Mill 2520-0685 5.0 A GOST 6637-80

Official publication Reproduction prohibited

mm Table I

Mill type 1 1 Mill type 2

Module t p0

Notes:

1. Milling cutters for the 1st row of modules are preferred for use.

2. The size taken in brackets is not recommended.

3 For cutters manufactured in a centralized manner, the rake angle in the normal section is 0 °

1.4. Ш bottom groove - according to GOST 9472.

It is allowed to produce a keyway in cutters with a tolerance range of width B - B12, and height Ci - H14.

1.5. The estimated dimensions of the cutters are indicated in Appendix 1.

1.6. The profile dimensions of the cutter teeth are indicated in Appendix 2.

1.7. The purpose of the cutters is indicated in Appendix 3.

2. TECHNICAL REQUIREMENTS

2.1. Milling cutters must be manufactured in accordance with the requirements of this standard according to working drawings approved in the prescribed manner.

2.2. Mills must be made of high-speed steel in accordance with GOST 19265. It is allowed to manufacture cutters from other grades of high-speed steel that ensure the durability of the cutters in accordance with the requirements of this standard.

2.3. The hardness of high-speed steel cutters is 63... 66 HRC 3. The hardness of cutters made of high-speed steel with a vanadium content of 3% or more, cobalt 5% or more is 64... 66 HRC 3.

2.2, 2.3. (Changed edition, Amendment No. 1).

2.4. There should be no cracks, hairlines, holes, or traces of corrosion on the surface of the cutter. The appearance of a cutter manufactured for export must correspond to the control sample agreed upon with the foreign trade organization.

2.5. There should be no nicks, burrs, traces of crushing, or burns on the working surfaces of the teeth, on the seating surface of the hole and on the end surfaces.

2.5a. The ground part of the cutters, ensuring the required profile accuracy, must be at least 1/2 of the tooth length along the outer diameter for cutters of modules up to 4 mm and 1/3 of the tooth length for cutters of modules over 4 mm.

The criterion for cutter dullness is wear on the back surface of the cutter teeth. Wear should not exceed the values set in the table. 2a.

table 2

(Introduced additionally, Amendment No. 1).

(Changed edition, Amendment No. 2).

2.6. The roughness parameters of cutter surfaces according to GOST 2789 should be no more than, microns;

mounting hole for accuracy class



front surface of teeth for class	accuracy


end surface and cylindrical surface
beads for accuracy classes A (modules from 0.5 to 3.5)*
A (modules sv 3.5 to 10)


back surface of the teeth, on the sides	sides,
at the top for accuracy classes* A (modules from 0.5 to 3.5) ....
A (modules sv 3.5 to 10)

* At the request of the consumer, the surface roughness of the ends of the beads is allowed Ra^.0.63 microns

2.7. Incomplete turns must be blunted so that the thickness of the upper part of the tooth along its entire length is at least 0.5 module.

(Changed edition, Amendment No. 1).

2.8. Unspecified maximum dimensional deviations: H16, N6, IT14

2.9. Tolerances and maximum deviations of the checked cutter parameters should not exceed the values specified in table. 2.

2 10. Average and 95% durability periods of cutters should! not less than those established in the table. 2a subject to the test conditions given in Section. 4.

(Introduced additionally, Amendment No. 1).

(Changed edition, Amendment No. 2).

1. Bore hole diameter deviation

2. Radial runout of the cylindrical surface of the burners

GOST *837-80 S.

3. Trimmer bevel surfaces of beads

4. Radial runout along the outer diameter

Fineness class	Module, mm
		St. 2 BEFORE. 3.5
	Tolerances and maximum* deviations, mKm

I. 6 GOST 6637-80

5. Deviation from straightness and inclination of the front surface at the working height of the tooth

grooves within a revolution

GOST vv37-80 S.

Click and designate the parameters being checked

7 Pax «Sh1Miaya error of the circumferential pitch of the chip flutes

The largest difference in deviations of actual circular steps from the nominal one, measured along an arc of a circle close to the pitch on one revolution_

8. Deviation of the direction of chip flutes per 100 mm of the length of the working part of the cutter

M-1199 LEO! 9 *e

9 Tooth profile deviations

10 Deviation of tooth thickness minus

Designation of tolerances and maximum deviations	Accuracy class
			St. to 10
		Tolerances and maximum deviations, microns

GOST 6637-80 C

1 Deviation of the cutter helix from tooth to tooth

12 Deviation of the cutter helix per revolution

10 GOST 6637-80

13. Deviation of the cutter helix at three revolutions

GOST 6637-80 C II

Name and designation of the parameters being checked

O L QJ X H ts

CJ 4>th O&H

14. Maximum pitch deviations (distance between adjacent tooth profiles of the same name)

15. Accumulated step error over the length of any three adjacent steps

Module, mm

1* GOST 6637-80

Notes

1 The maximum deviation of the mounting hole must be maintained at 60% of the length of each mounting belt. In the area of the keyway at the central angle, not exceeding 25% of the axis of symmetry in both directions, it is allowed to split the hole for cutters with a longitudinal keyway

1st group fd, f y , ft, fy , fda, fpto OR

Fpo, Tco, f x , F p p

2-group f d, f y, ft, F v; f d a, f Pt0 or

Fpo, Tco, fx, ffo, fpxO, fPx30

Cutters of accuracy class A are arrested according to the 1st group of checks, accuracy classes B, C - according to the 2nd group of checks (for cutters of class B, by agreement with the consumer, the 1st group of checks can be used).

2.11. The following must be marked on the end of each cutter: trademark of the manufacturer; cutter designation (last 4 digits);

module; profile angle;

accuracy class designation,

grade of material (it is allowed to mark the letters HSS instead of the steel grade; for steel grades containing cobalt - HSS Co); helix angle; helical groove pitch; year of issue.

2.12. By agreement with the consumer, a class A cutter must have a passport indicating deviations from the nominal dimensions.

2.13. Transport marking, marking of consumer containers and packaging - in accordance with GOST 18088.

2.11-2.13. (Introduced additionally, Amendment No. 2).

3 ACCEPTANCE

3.1. Acceptance rules - according to GOST 23726.

3.2. Tests for the average durability period are carried out once every three years, for the 95% durability period - once every two years, on at least 3 cutters.

(Changed edition, Amendment No. 2).

4 TEST METHODS

4.1. Tests of cutters must be carried out on gear hobbing machines that meet the standards of precision and rigidity established for them in accordance with GOST 659.

The cutters are tested on workpieces made of steel grade 45 according to GOST 1050 or steel grade 40X according to GOST 4543 with a hardness of 170... 207 HB.

A 5% by weight emulsol solution or industrial oil I-20A according to GOST 20799 is used as a cutting fluid.

Tests of cutters must be carried out in the modes specified in table. 3.

Table 3

Note. The cutting speed of cutters made of steel containing 3% or more vanadium or 5% or more cobalt should be 25% higher than the speed indicated in the table. 3.

(Changed edition, Amendment No. 1).

4.1a. Acceptance values for the average and specified service life of cutters must be no less than those indicated in the table. 4.

Tests for average and 95% durability periods are carried out on cutters of two standard sizes in the modulus range from 1 to 8 mm.

Table 4

(Introduced additionally, Amendment No. 1). (Changed edition, Amendment No. 2).

4.2. The performance of the cutters is checked within 10 minutes of machine time. After testing, the cutter should not have chipped or crushed cutting edges, should retain its cutting properties and should be suitable for further work.

(Changed edition, Amendment No. 1).

4.3. The parameters of the cutters must be controlled by measuring instruments with a measurement error of no more than:

a) when measuring linear dimensions - the values specified in GOST 8.051;

b) check the parameters according to clause 2.9 (14-15) on instruments whose error does not exceed those specified in GOST 17336;

c) when controlling the shape and location of surfaces - no more than 25% of the tolerance value for the parameter being tested.

4.4. The control of cutters according to clause 2.3 must be carried out in accordance with GOST 9013 on TR type devices in accordance with GOST 23677.

4.5. The surface roughness of clause 2.7 is checked by comparison with roughness samples according to GOST 9378 or with standard tools, the surfaces of which have limiting values of roughness parameters; the comparison is carried out visually using a magnifying glass LP-1-4 x according to GOST 25706.

(Changed edition, Amendment No. 1).

5. TRANSPORTATION AND STORAGE

Transportation and storage - according to GOST 18088.

APPENDIX J Required*

ESTIMATED DIMENSIONS OF MILLS

Dimensions, mm

Module t p0					Screw pitch chip

Note. Cutters with a helix angle of 5° or less can be produced with straight axial flutes.

APPENDIX 2 Mandatory

DIMENSIONS OF MILL TEETH PROFILE IN NORMAL SECTION

Table 1

Module Ш p0

table 2

Module t p0 Row

Notes:

1 Mills with a module from 1.0 to 2.5 mm can be manufactured without a radius or tip.

2 The shape of the cavity in the area below the line determined by the nominal height of the tooth is arbitrary.

3. Dimensions h a0 and L p are theoretical.

cutter accuracy class A - for splined shafts of the 8th degree of accuracy not GOST 6033-80, for splined shafts with tolerance fields of shaft tooth thickness S 3 H, S 3 C, S 3 x according to GOST 6033-51;

cutter accuracy class B - for spline shafts of the 9th degree of accuracy according to GOST 6033-80; for splined shafts with tolerance fields of shaft tooth thickness S Sa H, S 3a C, S 3 aX in accordance with GOST 6033-51;

cutter accuracy class C - for splined shafts of 10th and 11th degrees of accuracy according to GOST 6033-80; for splined shafts with a tolerance range of shaft tooth thickness S 4 m according to GOST 6033-51.

(Introduced additionally, Amendment No. 1).

(Changed edition, Amendment No. 2).

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Machine Tool and Tool Industry of the USSR

DEVELOPERS

A. N. Shevchenko, I. G. Lobanova

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated May 14, 1980 No. 2105

3. Verification period - 1992.

4. INSTEAD GOST 6637-53

5. REFERENCED REGULATORY TECHNICAL DOCUMENTS

Item number, application

GOST 8.051-81 GOST 659-89 GOST 1050-88 GOST 2789-73 GOST 4543-71 GOST 603 3-80 GOST 6033-51 GOST 9013-59 GOST 9 378-75 GOST 9472-90 GOST 17336-8 E GOST 18038- 83 GOST 19265-73 GOST 20799-88 GOST 23677-79 GOST 23726-79 GOST 25706-83

Introductory part, appendix 3

6. By Decree of the USSR State Standard No. 1735 dated November 13, 1991, the validity period was lifted

7. REISSUE (April 1994) with Amendments No. 1, 2, approved in March 1987, November 1991 (IUS 6-87, 2-92)

Editor L. L. Vladimirok Technical editor O. N. Nikitina Proofreader N. I. Gavrishchuk

Delivered to embankment 04/19/94. Subp. in the oven 27.05.94. Uel. p, l. 3.40. Uel. cr.-ott. 1.49 _Uch.-ed. l. 1.20. Shooting gallery 594 akz. Since 1358,

Order of “Knowledge* of Honor” Publishing house of standards, 107076, Moscow, Kolodezny per.. 14. Kaluga printing house of standards, st. Moskovskaya, 256. Zak. 876

GOST 6637-80

Group G23

STATE STANDARD OF THE USSR UNION

Finishing hob cutters for spline
SHAFT WITH INVOLVENT PROFILE

Specifications

Finishing involute spline hobs.Specifications

Date of introduction 1982-01-01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Machine Tool and Tool Industry of the USSR

DEVELOPERS

A.N.Shevchenko, I.G.Lobanova

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated May 14, 1980 N 2105

3. Verification period - 1992.

4. INSTEAD GOST 6637-53

5. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

	Item number, application
GOST 8.051-81
GOST 659-89
GOST 1050-88
GOST 2789-73
GOST 4543-71
GOST 6033-80	Introductory part, appendix 3
GOST 6033-51
GOST 9013-59
GOST 9378-93
GOST 9472-90
GOST 17336-80
GOST 18088-83
GOST 19265-73
GOST 20799-88
GOST 23677-79
GOST 23726-79
GOST 25706-83

6. By Decree of the USSR State Standard No. 1735 dated November 13, 1991, the validity period was lifted

7. REISSUE (May 1996) with Amendments No. 1, 2, approved in March 1987, November 1991 (IUS 6-87, 2-92)

This standard applies to solid hob finishing cutters for processing gear (spline) shafts with an involute profile in accordance with GOST 6033-80 and GOST 6033-51.

The requirements of the standard in parts 1, 2, 4, 5 and clause 3.2 are mandatory, other requirements of this standard are recommended.

1. TYPES AND MAIN DIMENSIONS

1.1. Milling cutters should be made of the following types:

1 - for processing shafts with a flat cavity;

2 - for processing shafts with a rounded cavity.

1.2. The cutters should be made right-handed with left-handed helical grooves of accuracy classes A, B and C.

1.3. The main dimensions of solid cutters must correspond to those indicated in the drawing and in Table 1.

Table 1

Type 1 cutter

Type 2 cutter

Module

Number of teeth

Designation

At-
change-
bridge

Designation

At-
change-
bridge

Prev. off

Notes:

1. Milling cutters for the 1st row of modules are preferred for use.

2. The size taken in brackets is not recommended.

3. For cutters manufactured in a centralized manner, the rake angle in the normal section is 0°.

An example of a symbol for a milling cutter with a module =5.0 mm, accuracy class A, type 1:

Mill 2520-0685 5.0 A GOST 6637-80

1.4. Keyway - according to GOST 9472.

It is allowed to produce a keyway in cutters with a tolerance range of width - B12, and height - H14.

1.5. The estimated dimensions of the cutters are indicated in Appendix 1.

1.6. The profile dimensions of the cutter teeth are indicated in Appendix 2.

1.7. The purpose of the cutters is indicated in Appendix 3.

2. TECHNICAL REQUIREMENTS

2.1. Milling cutters should be manufactured in accordance with the requirements of this standard according to working drawings approved in the prescribed manner.

2.2. Cutters should be made of high-speed steel in accordance with GOST 19265. It is allowed to manufacture cutters from other grades of high-speed steel that ensure the durability of the cutters in accordance with the requirements of this standard.

2.3. The hardness of high-speed steel cutters is 63...66 HRC. The hardness of cutters made of high-speed steel with a vanadium content of 3% or more, cobalt 5% or more is 64...66 HRC.

2.2, 2.3. (Changed edition, Amendment No. 1).

2.5. There should be no nicks, burrs, traces of crushing, or burns on the working surfaces of the teeth, on the seating surface of the hole and on the end surfaces.

The criterion for cutter dullness is considered to be wear on the back surface of the cutter teeth. Wear should not exceed the values set in Table 2a.

Table 2a

Module, mm	Duration period, min	Allowable wear, mm
	average
From 0.5 to 0.8
" 0,8 " 8,0
" 8,0 " 10,0

2.6. The roughness parameters of cutter surfaces according to GOST 2789 should be no more than, microns:

Mounting hole for accuracy classes:

The front surface of the teeth for accuracy classes:

The surface of the ends and the cylindrical surface of the shoulders for accuracy classes:

	A (modules from 0.5 to 3.5)*
	A (modules from 3.5 to 10)

________________
* At the request of the consumer, a surface roughness of the ends of the beads of 0.63 microns is allowed.

Back surface of teeth, on sides, on top for accuracy classes:

	A (modules from 0.5 to 3.5)
	A (modules from 3.5 to 10)

2.7. Incomplete turns must be blunted so that the thickness of the upper part of the tooth along its entire length is at least 0.5 module.

(Changed edition, Amendment No. 1).

2.8. Unspecified maximum deviations of dimensions: H16, h16, .

2.9. Tolerances and maximum deviations of the checked cutter parameters should not exceed the values specified in Table 2.

2.10. The average and 95% durability periods of cutters must be no less than those established in Table 2a, subject to the test conditions given in Section 4.

(Introduced additionally, Amendment No. 1).

(Changed edition, Amendment No. 2).

table 2

			Module, mm
Name and designation of the parameters being checked	Designation tolerances and prev. off	Accuracy class ness		St. 1 to 2	St. 2 to 3.5	St. 3.5 to 6	St. 6 to 10
			Approvals and prev. off, µm
1. Bore hole diameter deviation
2. Radial runout of the cylindrical surface of the shoulders


3. Face runout of the bead surfaces


4. Radial runout along the outer diameter


5. Deviation from straightness and inclination of the front surface at the working height of the tooth


6. The largest difference between adjacent circumferential pitches of chip flutes within a revolution


7. Cumulative error of circumferential pitch of chip flutes

The largest difference in deviations of actual circular steps from the nominal one, measured along an arc of a circle close to the pitch on one revolution
8. Deviation of the direction of chip flutes per 100 mm of the length of the working part of the cutter


9. Tooth profile deviations


10. Deviation of tooth thickness to minus


11. Deviation of the cutter helix from tooth to tooth


12. Deviation of the cutter helix per revolution


13. Deviation of the cutter helix at three revolutions


14. Maximum pitch deviations (distance between adjacent tooth profiles of the same name)


15. Accumulated step error over the length of any three adjacent steps

Notes:

1. The maximum deviation of the landing hole must be maintained at 60% of the length of each landing belt. In the area of the keyway at the central angle, not exceeding 25% of the axis of symmetry in both directions, it is allowed to drill holes for cutters with a longitudinal keyway.

1st group - , , , , , or

2nd group - , , , ; ; or

Milling cutters of accuracy class A are certified according to the 1st group of tests; accuracy classes B, C - according to the 2nd group of checks (for class B cutters, by agreement with the consumer, the 1st group can be used

inspection group).

2.11. The average and established periods of service life of cutters must be no less than those established in Table 2a, subject to the test conditions given in Section 4.

(Introduced additionally, Amendment No. 1).

2.12. The following must be marked on the end of each cutter:

Trademark of the manufacturer;

Designation of the cutter (last 4 digits);

Profile angle;

Accuracy class designation;

Material grade (it is allowed to mark the letters HSS instead of the steel grade; for steel grades containing cobalt - HSS Co);

Helix angle;

Helical groove pitch;

Year of issue.

2.13. By agreement with the consumer, a class A cutter must have a passport indicating deviations from the nominal dimensions.

2.14. Transport marking, marking of consumer containers and packaging - in accordance with GOST 18088.

2.12-2.14. (Introduced additionally, Amendment No. 2).

3. ACCEPTANCE

3.1. Acceptance rules - according to GOST 23726.

3.2. Tests for the average durability period are carried out once every three years, for the 95% durability period - once every two years on at least three cutters.

(Changed edition, Amendment No. 2).

4. TEST METHODS

4.1. Tests of cutters must be carried out on gear hobbing machines that meet the standards of accuracy and rigidity established for them in accordance with GOST 659.

Milling cutters are tested on workpieces made of steel grade 45 according to GOST 1050 or steel grade 40X according to GOST 4543 with a hardness of 170...207 HB.

A 5% by weight emulsol solution or industrial oil I-20A according to GOST 20799 is used as a cutting fluid.

Tests of cutters must be carried out in the modes indicated in Table 3.

Table 3

Module, mm	Feed, mm/rev		Cutting speed, m/min
	on solid metal	by cut tooth	on solid metal	by cut tooth
From 0.5 to 0.8
From 0.8 to 3.5
From 3.5 to 6.0
From 6.0 to 8.0
From 8.0 to 10.0

Note. The cutting speed of cutters made of steel with a vanadium content of 3% or more or cobalt content of 5% or more should be 25% higher than the speed indicated in Table 3.

(Changed edition, Amendment No. 1).

4.1a. Acceptance values for the average and specified service life of cutters must be no less than those indicated in Table 4.

Tests for average and 95% durability periods are carried out on cutters of two standard sizes in the modulus range from 1 to 8 mm.

Table 4

Module, mm	Acceptance values of durability periods, min
	average	95%
From 0.5 to 0.8

" 8,0 " 10,0

(Introduced additionally, Amendment No. 1, amended edition, Amendment No. 2).

4.2. The performance of the cutters is checked within 10 minutes of machine time. After testing, the cutter should not have chipped or crumpled cutting edges, should retain its cutting properties and be suitable for further work.

(Changed edition, Amendment No. 1).

4.3. The parameters of the cutters must be controlled by measuring instruments with a measurement error of no more than:

a) when measuring linear dimensions - the values specified in GOST 8.051;

b) the parameters according to clause 2.9 (Table 2, clauses 14, 15) are checked on instruments whose error does not exceed those specified in GOST 17336;

c) when controlling the shape and location of surfaces - no more than 25% of the tolerance value for the parameter being tested.

4.4. The control of cutters according to clause 2.3 must be carried out in accordance with GOST 9013 on TR type devices in accordance with GOST 23677.

4.5. Surface roughness (clause 2.6) is checked by comparison with roughness samples in accordance with GOST 9378 or with standard tools, the surfaces of which have limiting values of roughness parameters; comparison is carried out visually using a magnifying glass LP-1-4 according to GOST 25706.

(Changed edition, Amendment No. 1).

5. TRANSPORTATION AND STORAGE

5.1. Transportation and storage of cutters - in accordance with GOST 18088.

(Changed edition, Amendment No. 2).

APPENDIX 1 (mandatory). ESTIMATED DIMENSIONS OF MILLS

ANNEX 1
Mandatory

Dimensions, mm

Module					Helical flute pitch

Official publication

PUBLISHING HOUSE OF STANDARDS M o t k ■ a

UDC 621.914.6:006.354 Group G21

STATE STANDARD OF THE USSR UNION

Finishing hob cutters for splined shafts with involute profile

Specifications

Finishing involute spline hobs. Specifications

okp ze i8i6

Date of introduction 01/01/82

This standard applies to solid hob finishing cutters for processing gear (spline) shafts with an involute profile in accordance with GOST 6033-80 and GOST 6033-51.

The requirements of the standard regarding section. 1, 2, 4, 5 and clause 3.2 are mandatory, other requirements of this standard are recommended.

1. TYPES and MAIN DIMENSIONS

1.1. The cutters must be made of the following types:

1 - for processing shafts with a flat cavity;

2 - for processing shafts with a rounded cavity.

1.2. The cutters must be made right-handed with left-handed helical grooves of accuracy classes A, B and C.

1.3. The main dimensions of solid cutters must correspond to those indicated in the drawing and in the table. 1.

An example of a symbol for a milling cutter with a module /Ppo=5.0 mm, accuracy class A, type 1:

Official publication Reproduction prohibited

% GOST ttS7-S#

mm Table!

Type 1 cutter

Type 2 cutter

Module m n0

1 Applicability

Notes:

1. Milling cutters for the 1st row of modules are preferred for use.

2. The size taken in brackets is not recommended.

3 For cutters cut in a centralized manner, the rake angle in the normal section is 0 °

It is allowed to produce a keyway in cutters with a tolerance range of width L - B12, and height C\ - H14.

1.5. The estimated dimensions of the cutters are indicated in Appendix 1.

1.6. The profile dimensions of the cutter teeth are indicated in Appendix 2.

1.7. The purpose of the cutters is indicated in Appendix 3.

2. TECHNICAL REQUIREMENTS

2.1. Milling cutters must be manufactured in accordance with the requirements of this standard according to working drawings approved in the prescribed manner.

2.2. Milling cutters must be made of high-speed steel in accordance with GOST 19265. It is allowed to manufacture cutters from other grades of high-speed steel that ensure the durability of the cutters in accordance with the requirements of this standard.

2.3. The hardness of high-speed steel cutters is 63... 66 HRC. The hardness of cutters made of high-speed steel with a vanadium content of 3% or more, cobalt 5% or more is 64 ... 66 HRC 3.

2.2, 2.3. (Changed edition, Amendment No. 1).

2.5. There should be no nicks, burrs, traces of crushing, or burns on the working surfaces of the teeth, on the seating surface of the hole and on the end surfaces.

The criterion for cutter dullness is wear on the back surface of the cutter teeth. Wear should not exceed the values set in the table. 2a.

(Introduced additionally, Amendment No. 1).

(Changed edition, Amendment No. 2).

2.6. The roughness parameters of cutter surfaces according to GOST 2789 should be no more than, microns:

mounting hole for accuracy class

Sun. . ... . . Ra 0.63

tooth front surface for accuracy class

V, S. .... . , Rz 6.3

end surface and cylindrical surface of shoulders for accuracy classes

A (modules from 0.5 to 3.5)*. . . . Ra 0.32

A (modules St 3.5 to 10) Ra 0.63

WITH. . . . Ra 1.25

rear surface of the teeth, on the sides, on the top for accuracy classes -

A (modules from 0.5 to 3.5) ...... Rz 1.6

A (modules sv 3.5 to 10) ... Rz 3.2

IN. . . . ...Rz 2.2

WITH. . ....... Rz 6.3

* At the request of the consumer, the surface roughness of the ends of the beads is allowed Ra^.0.63 microns

2.7. Incomplete turns must be blunted so that the thickness of the upper part of the tooth along its entire length is at least 0.5 module.

(Changed edition, Amendment No. 1).

2.8. Unspecified maximum deviations of dimensions: H16, N6,

T. 2.

2.9. Tolerances and maximum deviations of the checked cutter parameters should not exceed the values specified in table. 2.

2 10. The average and 95% periods of durability of cutters should be no less than those established in the table. 2a subject to the test conditions given in Section. 4.

(Introduced additionally, Amendment No. 1).

(Changed edition, Amendment No. 2).

1. Bore hole diameter deviation

2. Radial runout of the cylindrical surface of the shoulders

- THEM

Designation of tolerances ■ maximum deviations	Accuracy class	Module, mm
			St. 3.1 to 5	ev. at to 10

says "37-80 S. S

Name and designation of the parameters being checked

3. Tornov** tusks" surfaces of beads

4. Radial runout along the outer diameter

Continuation of the table. 2

Designation of tolerances and maximum deviations	Accuracy class	Module, mm
			St. 2 b.c. 3.5	St. 3.5 to 6
		Tolerances and maximum deviations, microns

О»-£€99 JL30J 9 *0

Continuation of the table. L

position at working tooth height

U

grooves within a revolution

Designation of tolerances and maximum deviations	Accuracy class	Module, mm
			St. 2 b.c. 3.5	St. 3.5 to 6	St. 6 to no.
		Tolerances and maximum deviations, microns