INTERSTATE STANDARD

TOOL SHANKS WITH TAPER 7:24

Official edition

INTERSTATE COUNCIL FOR STANDARDIZATION. METROLOGY AND CERTIFICATION Minsk

Foreword

1 DEVELOPED by Gosstandart of Russia

INTRODUCED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification

2 ADOPTED by the Interstate Council for Standardization,

3. The standard complies with the international standard ISO 297-88 for 7:24 taper tool shanks and fully complies with ISO 7388-1-83

Version 1

Maximum deviation of the position of the main plane.

/ - main plane; 2 - tool attachment area

Dimensions for reference

Dimensions comply with ISO 297-88. except for the sizes.

Table 1
t. not Sole L*'s ■eeee no more
enclosed in brackets (see appendix)

Notes:

1. Dimensions in brackets for machines designed before 01/01/94.

2. Dimensions a, D 2 , / apply to tools for which a clamp is provided on the front side of the flange.

3. Groove for exit grinding wheel- according to GOST 8820. It is allowed to manufacture shanks without a groove for the grinding wheel to exit between the base diameter and the flange. In this case, the diameter of the cylindrical transitional surface D^=D ~0.5.

4. By agreement with the consumer, it is allowed to increase the size D t to values ​​equal to the diameter of the outer surface of the spindle end in accordance with GOST 30064-93.

* Maximum deviation of the position of the main plane.

** Dimensions define the tool grip space.

It. at least

Shank dimensions according to ISO 7388-1-83 (see appendix).

Notes:

1. The diameter of the cylindrical part /) 5 must satisfy the following relationship:

Between the base diameter and the flange, make a groove for the output of the grinding wheel in depth according to GOST 8820. Groove width for cones 30 and 40-1.6 mm. for cones 45 and 50-3.0 mm;

An increase in the size of /, subject to the fulfillment of the ratio, while the grooves for the key with a width b can be non-through with parallel sides with a length of at least / 44

Notes:

1. Groove for the exit of the grinding wheel - according to GOST 8820.

2. By agreement with the consumer, it is allowed:

Between the base diameter and the flange, make a groove for the exit of the grinding wheel with a depth according to GOST 8820, the width of the groove for cones 30 and 40 is 1.6 mm, for cones 45 and 50 - 3.0 we;

Increasing the size / to a value not exceeding: / + L, while the grooves for the key with a width b can be made non-through with parallel sides with a length of at least /;

Making a groove with size / a.

3. The dimensions and shape of the center hole must correspond to those indicated in Fig. 4 and in table. 4.

4. Unspecified limit deviations of dimensions: H14, N4, IT 14

5. The degree of accuracy of the cones AT4, AT5, the tolerances of the angle and shape of the cone - according to GOST 19860. The deviation of the cone angle from the nominal should be in the "plus".

6. Surface hardness of the conical part of the shanks - 51 ... 57 HRC,.

And execution.

Morse taper and metric taper

Morse taper is one of the most widely used tool holders. Introduced by Stephen A. Morse around 1864.

Morse taper is divided into eight sizes, from KM0 before KM7(English MT0-MT7, German MK0-MK7). Taper from 1:19.002 to 1:20.047 (taper angle from 2°51'26" to 3°00'52", taper slope from 1°25'43" to 1°30'26") depending on the size.

Metric taper

As the machine tool industry developed, it was necessary to expand the range of sizes of Morse cones both up and down. At the same time, for the new cone sizes, we chose a taper of exactly 1:20 (the cone angle is 2°51’51", the cone slope is 1°25’56") and named them metric cones(eng. Metric taper). The size of metric cones is indicated by the largest diameter of the cone in millimeters. GOST 25557-2006 also defines reduced metric cones No. 4 and No. 6 (English ME4, ME6) and large metric cones No. 80, 100, 120, 160, 200 (English ME80 - ME200).

There are no structural differences between Morse taper and metric taper.

Dimensions of the outer and inner cone (according to GOST 25557-2006), mm

Table 1

	Cone designation	Taper	D	D1	d	d1	d2	d 3 max	d4max	d5	l 1max	l 2 max	l 3max	l 4max	l 5 min	l 6
Metric	№ 4	1:20	4	4,1	2,9	-	-	-	2,5	3	23	25	-	-	25	21
	№ 6	1:20	6	6,2	4,4	-	-	-	4	4,6	32	35	-	-	34	29
morse	KM0	1:19,212	9,045	9,2	6,4	-	6,1	6	6	6,7	50	53	56,3	59,5	52	49
	KM1	1:20,047	12,065	12,2	9,4	M6	9	8,7	9	9,7	53,5	57	62	65,5	56	52
	KM2	1:20,020	17,780	18	14,6	M10	14	13,5	14	14,9	64	69	75	80	67	62
	KM3	1:19,922	23,825	24,1	19,8	M12	19,1	18,5	19	20,2	80,1	86	94	99	84	78
	KM4	1:19,254	31,267	31,6	25,9	M16	25,2	25,2	24	26,5	102,5	109	117,5	124	107	98
	KM5	1:19,002	44,399	44,7	37,6	M20	36,5	35,7	35,7	38,2	129,5	136	149,5	156	135	125
	KM6	1:19,180	63,348	63,8	53,9	M24	52,4	51	51	54,6	182	190	210	218	188	177
	KM7	1:19,231	83,058					-					285.75	294.1
Metric	№ 80	1:20	80	80,4	70,2	M30	69	67	67	71,5	196	204	220	228	202	186
	№ 100	1:20	100	100,5	88,4	M36	87	85	85	90	232	242	260	270	240	220
	№ 120	1:20	120	120,6	106,6	M36	105	102	102	108,5	268	280	300	312	276	254
	№ 160	1:20	160	160,8	143	M48	141	138	138	145,5	340	356	380	396	350	321
	№ 200	1:20	200	201	179,4	M48	177	174	174	182,5	412	432	460	480	424	388

Short Morse Taper

For many applications, the length of the Morse taper has proven to be excessive. Therefore, nine sizes of shortened Morse tapers were invented, obtained by removing the thicker part of the Morse taper. The number in the designation of the short cone is the diameter of the new thick part of the cone in mm. Russian standard for short cones GOST 9953-82 “Shortened tool cones. Main dimensions.

• B7- shortened to 14 mm KM0.
• B10, B12- shortened to 18 and 22 mm respectively KM1.
• B16, B18- shortened to 24 and 32 mm respectively KM2.
• B22, B24- shortened to 45 and 55 mm respectively KM3.
• B32- shortened to 57 mm KM4.
• B45- shortened to 71 mm KM5.

Often the buyer, when ordering an auxiliary tool for the machine, is convinced that by specifying “spindle with SK40 taper” when ordering, he will definitely get what he wants. When the tool he bought does not fit the machine, the customer is extremely surprised: “How is it, I used to buy the “SK40 Arbor with a 7:24 taper” and there were no problems, but now I bought the “same” SK40, and he suddenly doesn't fit." Let's try to understand the situation.

The customer is right and wrong at the same time. The main problem lies in the notation itself. The letters SK refer only to the taper of the mandrel shank and are short for the German Steilkegel - steep taper. A steep taper in this case refers to mandrels with a taper of 7:24. Thus, when specifying SK when ordering, the customer determines only the type of shank. Other common shank types in the machine tool industry are HSK short hollow taper, Morse taper MK, modular systems KM and Capto. The number 40 indicates the size of the shank. In this part, the sanctuary indicated everything correctly. His mistake lies in the fact that in addition to the type and size of the shank, it is necessary to indicate the standard according to which the shank is made.
In the USSR, there was GOST 25827-83 “Tool shanks with a 7:24 taper”. Due to the fact that this GOST did not correspond to any of the existing international standards, it was revised in 1992. Many significant changes and additions were made - and it began to fully comply with the ISO 7388 / 1-83 standard. The "new" GOST was assigned a new Russian number - GOST R 50071-92. At the same time, the old GOST of 1983 was completely "lost", as a result of which in 1993 it was revised again. It was decided to return the old GOST 25827 number familiar to everyone, and the Russian GOST R 50071-92 (which was issued "to replace GOST 25827-83 and GOST 24644-81 in terms of mandrels with a 7:24 cone") was canceled. Thus, in Russia today there is only one GOST 25827-93 “Tool shanks with a 7:24 taper”.
This GOST standardizes three shank designs:

1. Shanks according to "version 1" are used for machines with manual tool change and comply with DIN 2080.
2. According to "version 2" - for machines with automatic tool change, they comply with ISO 7388 / 1-83, which is the same as DIN 69871.
3. According to “version 3” (also for automatic tool change) they do not correspond to any Western analogues and have a note: “tool with shanks for equipment up to 01/01/94”.

It's all in our country. What is the situation abroad?
Today in Europe, the most common shanks with DIN execution - German standard on the basis of which the ISO international standard was created. On Japanese machines, MAS BT shanks (Japanese standard JIS B 6339) predominate. Machine tools with spindles according to this standard are increasingly wide use in Europe, accordingly, the range of auxiliary tools with this type of connection is expanding. In America, auxiliary tools with CAT/ANSI shanks are common. Some firms manufacture machines with spindle attachment own design(for example, Mazak). What are the fundamental differences between these tails? The article provides sketches of some standard shanks and tables with basic dimensions.

Most European machines use auxiliary tools according to DIN 69871 (ISO 7388/1-83). There are three versions of this standard:

• form "A" - without a central hole for coolant supply (corresponds to Russian GOST 25827-93 version 2);
• form "AD" - with a central hole for supplying coolant through the center of the spindle;
• form "B" - with side holes for coolant supply, located at the end of the flange under the grip of the manipulator.

Form "AD" is similar to form "A", only with a through central hole.
Execution "B" is structurally different for various firms, but the functions remain unchanged.
Execution 1 according to GOST 25827-93 (for manual tool change) today fully complies with DIN 2080.
Many machines of domestic and Western production today are focused specifically on DIN (ISO), machines with a spindle design for MAS BT are less common. Most of the companies that produce auxiliary tools (including Russian ones) offer a full range of both standards.
When buying a machine, it is still better to once again clarify which version of the spindle is offered to the customer. Often, machine tool manufacturers indicate only the size of the auxiliary tool without indicating which standard the spindle is made to. If there is a choice, it is better to choose a machine with an auxiliary tool that is already used in your enterprise. If the company offers without alternative a machine with a type of spindle not previously used in your production, it is better to contact the company offering the corresponding auxiliary tool and find out from it how wide the range of tools of this standard is available. Otherwise, it will take a long time to look for a source for acquiring the necessary auxiliary tool.
With all the variety of the considered auxiliary tool, there is partial interchangeability. All tools of the same size have the same base diameter and approximately the same base length. Most often, the difficulty arises only with automatic tool change, when the manipulator takes the manipulator from the machine magazine. Instruments various standards have different shape and dimensions of the groove for the capture of the manipulator, as well as different distance from the spindle reference plane to the groove axis. With manual change, this problem does not arise. Since each standard has its own form of rod for clamping the mandrel in the machine spindle, it is necessary to check whether the rod of this standard can be used on a given machine, or whether a special adapter rod must be made. It is with the help of adapter rods that an auxiliary tool made according to DIN 69871 can be fixed on a machine with a spindle according to GOST 25897-93 version 3. It is also recommended to check the base length of the cone, since it also differs slightly for different standards.

GOST 25827-93
(ISO 7388-1-83)

Group G27

INTERSTATE STANDARD

TOOL SHANKS WITH TAPER 7:24

Dimensions

Tool shanks with 7/24 taper. Dimensions

OKP 39 2800

Introduction date 1995-01-01

Foreword

1 DEVELOPED by Gosstandart of Russia

INTRODUCED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification

2 ADOPTED by the Interstate Council for Standardization, Metrology and Certification on October 21, 1993

Voted to accept:

State name	Name of national authority for standardization
Republic of Kyrgyzstan	Kyrgyzstandart
The Republic of Moldova	Moldovastandard
the Russian Federation	Gosstandart of Russia
The Republic of Tajikistan	Tajikstandart
Turkmenistan	Turkmenglavstate inspection

3. The standard complies with the international standard ISO 297-88 for 7:24 taper tool shanks and fully complies with ISO 7388-1-83

4 INTRODUCED TO REPLACE GOST 25827-83 and GOST 24644-81 in terms of mandrels with a cone 7:24

INFORMATION DATA

REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS

	Item number

This International Standard applies to 7:24 taper tool shanks for manual and automatic tool changers.

The requirements of this standard are mandatory, except for those set out in notes 3 and 4 to table 1 and in notes to tables 2-4.

1. Tool shanks must be made in the following versions:

1 - for manual change of tools with cones from 30 to 80;

2 and 3 - for automatic tool change with tapers from 30 to 50.

2. The dimensions of the tool shanks must correspond to:

execution 1 - indicated in drawing 1 and in table 1;

execution 2 - indicated in drawing 2 and in table 2;

execution 3 - indicated in drawing 3 and in table 3.

Note. Tool with shank version 3 - for equipment designed before 01.01.94.

Damn.1. Tool shank dimensions. Version 1

_________________

1 - main plane; 2 - tool attachment area

Table 1

Cone designation tool shank

Sky- more

Sky- more

±0.1 (±0.5)

±0.2 (±0.4)

Not me- her

Sky- more

_________________
* Dimensions for reference.

Dimensions are in accordance with ISO 297-88, except for dimensions in brackets (see appendix)

Notes:

1. Dimensions in brackets for machines designed before 01/01/94.

2. Dimensions , , apply to tools for which a clamp is provided on the front side of the flange.

3. Groove for the exit of the grinding wheel - according to GOST 8820. It is allowed to manufacture shanks without a groove for the grinding wheel to exit between the base diameter and the flange. In this case, the diameter of the cylindrical transitional surface =.

4. By agreement with the consumer, it is allowed to increase the size to values ​​​​equal to the diameter of the outer surface of the end of the spindle in accordance with GOST 30064-93.

Damn.2. Execution 2

_________________
* Maximum deviation of the position of the main plane.



*** Size for reference.

1 - main plane; 2
cutting edge tool; 3 - measuring roller; 4 - tool attachment area

table 2

No more

, at least

_________________
* Shank dimensions according to ISO 7388-1-83 (see appendix).

Notes:

1. The diameter of the cylindrical part must satisfy the following relationship:

GOST 8820. Groove width for cones 30 and 40 - 1.6 mm, for cones 45 and 50 - 3.0 mm;

- increase in size, subject to the fulfillment of the ratio, while the grooves for the key with a width can be non-through with parallel sides with a length of at least ;

Damn.3. Version 3

_________________
* Maximum deviation of the position of the main plane.

** Dimensions define the tool grip space.

1 - main plane; 2 - base of reference for determining the position
cutting edge of the tool; 3 - measuring roller

Table 3

Tool shank taper designation

No more

Not less than

No more

Notes:

1. Groove for the exit of the grinding wheel - according to GOST 8820.

2. By agreement with the consumer, it is allowed:

- between the base diameter and the flange, make a groove for the exit of the grinding wheel with a depth according to GOST 8820, the width of the groove for cones 30 and 40 is 1.6 mm, for cones 45 and 50 - 3.0 mm;

- increasing the size to a value not exceeding: , while the grooves for the key with a width can be made blind with parallel sides with a length of at least ;

- production of a groove with a size of .

3. The dimensions and shape of the center hole must correspond to those indicated in Fig. 4 and in Table 4.

Damn.4. Dimensions and shape of the center hole. Versions 1, 2

________________
* Dimensions for reference.

** For manual tool change - as agreed with the consumer.

4. Unspecified limit deviations of dimensions: H14, h14, ±

5. The degree of accuracy of the cones AT4, AT5, the tolerances of the angle and shape of the cone - according to GOST 19860. The deviation of the cone angle from the nominal should be in the "plus".

6. Surface hardness of the conical part of the shanks - 51 ... 57 HRC.

Table 4

Tool shank taper designation		, no more	, no more		, at least	, at least			6H (7H)

Notes:

1. The size enclosed in brackets is for machines designed before 01/01/94.

2. For machines with manual tool change for size, it is allowed to use the H9 tolerance field, the maximum deviation of the size is not regulated.

3. Groove for the exit of the grinding wheel (pos.1) - as agreed with the consumer.


Example symbol shank version 2 with taper 30:

Shank 2-30 GOST 25827-93

APPENDIX (reference). COMPLIANCE OF THIS STANDARD WITH INTERNATIONAL STANDARDS ISO 297-88, ISO 7388/1-83

APPENDIX
Reference

COMPLIANCE OF THIS STANDARD WITH INTERNATIONAL STANDARDS
ISO 297-88, ISO 7388/1-83

The dimensions of the shanks of tools with a 7:24 taper for manual tool change, established in this standard, fully cover the nomenclature of their sizes according to the international standard ISO 297-88 and are shown in Fig. 1 and in Table 1; for automatic tool change - fully comply with ISO 7388-1-83 and are shown in Figure 2 and Table 2.

Additionally, the standard includes requirements for the dimensions of tool shanks with a 7:24 taper for automatic tool change (version 3), not provided for by international standards, requirements for degrees of accuracy of shanks, taper angle tolerances and shape tolerances, surface hardness of the conical part of the shank.



The text of the document is verified by:
official publication
M.: Publishing house of standards, 1994

GOST 19860-93

Group G81

INTERSTATE STANDARD

INTERNAL AND EXTERNAL CONES 7:24

Tolerances

Internal and external 7:24 tapers.
Tolerances

OKS 25.080*
OKP 39 0000

____________________

* In index " National Standards"2006
OKS 25.080.01. - Note.

Introduction date 1996-01-01

Foreword

1 DESIGNED BY THE RUSSIAN FEDERATION

INTRODUCED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification

2 ADOPTED by the Interstate Council for Standardization, Metrology and Certification 15.03.94

State name	Name of the national standardization body
The Republic of Azerbaijan	Azgosstandart
Republic of Belarus	Belstandard
The Republic of Kazakhstan	State Standard of the Republic of Kazakhstan
The Republic of Moldova	Moldovastandard
the Russian Federation	Gosstandart of Russia
Turkmenistan	Turkmenglavstate inspection
The Republic of Uzbekistan	Uzgosstandart
Ukraine	State Standard of Ukraine

3 Resolution of the Committee Russian Federation on standardization, metrology and certification dated 28.06.95 N 329, the interstate standard GOST 19860-93 was put into effect directly as state standard Russian Federation since January 1, 1996

4 INSTEAD OF GOST 19860-74

1 AREA OF USE

1 AREA OF USE

This standard applies to cones in accordance with GOST 15945 with a taper of 7:24 designation from 30 to 80 and establishes tolerances for angles and shapes of cones from 3 to 7 degrees of accuracy.

The requirements of this standard are mandatory.

2 REGULATORY REFERENCES

GOST 8908-81 Basic norms of interchangeability. Normal angles and angle tolerances

GOST 15945-82 Internal and external cones with a taper of 7:24. Dimensions

3 ANGLE AND SHAPES TOLERANCES

3.1 The dimensions and tolerances of the corners of the outer and inner cones must correspond to those indicated in the figure and in table 1.

________________
* Size for reference.

** - the base distance of the cone is specified in the standards for specific products

1 - main plane; 2 - base plane

Table 1

Dimensions in mm

Cone designations				Angle tolerance, microns, cone according to GOST 8908

Conventional designation of cones - according to GOST 15945 with the addition of the degree of accuracy of the cone according to this standard, for example:

Cone 50 AT5 GOST 15945-82

3.2 Limit deviations of the base distance of the cone should be selected from the range: ±0.4; ±0.2; ±0.1; ±0.05 mm.

3.3. Cone shape tolerances should be as specified in Table 2.

table 2

Designation cones	Name admission	Form tolerance, microns, for degrees of accuracy
30; 35	Straightness tolerance
40; 45
50; 55
60; 65
70; 75
80
30; 35; 40;	roundness tolerance
45; 50;
55; 60
65; 70; 75; 80