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Taper size chart 7 24 35. Normal angles and tool tapers. Basic information about shanks and their designation

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

Group G27

INTERSTATE STANDARD

TOOL SHANKS WITH CONE 7:24

Dimensions

Tool shanks with 7/24 taper. Dimensions

OKP 39 2800

Date of introduction 1995-01-01

Preface

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.

The following voted for adoption:

State name	Name of the national authority on standardization
Republic of Kyrgyzstan	Kyrgyzstandard
Republic of Moldova	Moldovastandard
Russian Federation	Gosstandart of Russia
Republic of Tajikistan	Tajikstandard
Turkmenistan	Turkmen State Inspectorate

3. The standard complies with the international standard ISO 297-88 regarding shank dimensions for 7:24 taper tools and is fully compliant with ISO 7388-1-83

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

INFORMATION DATA

REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

	Item number

This standard applies to tool shanks with a 7:24 taper for manual and automatic tool changing.

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 manufactured in the following versions:

1 - for manually changing tools with cones from 30 to 80;

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

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

execution 1 - indicated in Figure 1 and Table 1;

execution 2 - indicated in Figure 2 and Table 2;

execution 3 - indicated in Figure 3 and Table 3.

Note. Tools with shanks version 3 - for equipment designed before 01/01/94.

Damn.1. Tool shank sizes. Version 1

_________________

1 - main plane; 2 - tool mounting 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 correspond to ISO 297-88, except for dimensions in parentheses (see annex)

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. Exit groove grinding wheel- according to GOST 8820. It is possible 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 transition surface =.

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

Damn.2. Version 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 mounting area

Table 2

No more

, no less

_________________
* 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. 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 provided that the ratio is met, while the grooves for the key width can be non-through with parallel sides with a length of at least this value;

Damn.3. Version 3

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

** Dimensions determine the space for gripping the tool.

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

Table 3

Tool shank taper designation

No more

No less

No more

Notes:

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

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

- between the base diameter and the flange, make a groove for the exit of the grinding wheel with a depth in accordance with 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: , in this case, the grooves for the key with a width can be made non-through with parallel sides of a length not less than the value;

- making a groove with size .

3. Dimensions and shape center hole must correspond to those indicated in Figure 4 and Table 4.

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

________________
*Dimensions for reference.

** For manual tool change - by agreement with the consumer.

4. Unspecified maximum dimensional deviations: H14, h14, ±

5. The degree of accuracy of AT4, AT5 cones, tolerances of the angle and shape of the cone - according to GOST 19860. Place the deviation of the cone angle from the nominal one in “plus”.

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

Table 4

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

Notes:

1. Dimensions in parentheses are for machines designed before 01/01/94.

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

3. Groove for the exit of the grinding wheel (item 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

APPLICATION
Information

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

The dimensions of tool shanks with a 7:24 taper for manual tool changing, established in this standard, fully cover the range of their sizes according to the international standard ISO 297-88 and are shown in Figure 1 and Table 1; for automatic tool changing - 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 cone for automatic tool changing (version 3), which are not provided for by international standards, requirements for the degrees of accuracy of shanks, cone angle tolerances and shape tolerances, surface hardness of the conical part of the shank.



The text of the document is verified according to:
official publication
M.: Standards Publishing House, 1994

To reduce the range of tools used in industrial metalworking equipment, various adapters from one cone to another are produced - for tools with a conical shank, as well as conical hole spindle.

Adapter type " outer cone- inner cone" is called a transition sleeve. An adapter of the "outer cone - outer cone" type is called a transition mandrel

.

Adapter bushings with taper 7:24

The main area of ​​application for the 7:24 tool cone is CNC machines equipped with a unit for automatic tool changing. This type of cone is devoid of the main disadvantage inherent in the Morse cone, which is fixed by self-jamming, which is difficult for automatic installation into the machine spindle. Also the 7:24 cone has larger area axial stop affecting the accuracy of installation, the ability to replace the rods designed for tightening and fixing in the spindle with a special mechanism.

Adapter bushings with Morse taper

These cones are made according to Morse standards (Stephen A. Morse - 19th century American inventor).

Standard cones of this type have several corresponding standard sizes, which are designated by the numbers 0,1,2,3,4,5,6. The selection of numbers of adapter bushings is carried out in accordance with those numbers that have the cone of the cutting tool.

Fixation of the conical shank in a specially provided hole in the spindle is achieved due to the friction force that occurs between conical surfaces. They ensure high accuracy of tool centering and also ensure quick tool change - using a special wedge.

Morse adapter bushings have two versions: short and long.

Adapter bushings with HSK taper

HSK-taper (from German: Hohlschaftkegel, hollow cone) is used in milling and turning-milling machining centers. Taper 1:10.

The HSK taper has several design varieties flanges, designated by the letters A, B, C, D, E, F. The size of the cone is indicated by the number of the largest flange diameter in mm (from 25 to 160).

The main advantages of the HSK connection: automatic quick tool change (which is very important in CNC machining centers), low weight, the ability to install turning tools in the spindle, good repeatability, and rigidity. As a rule, standard cutters square section are installed in a special intermediate mandrel, which, in turn, has an HSK cone. But sometimes cutters with HSK shank are also used.

Adapter bushings with R8 taper

The R8 cone is developed by Bridgeport Machines for its equipment. It was created specifically for collet clamps, and later began to be used as a tool cone. There is only one standard size.

Often the buyer, when ordering auxiliary tool for the machine, I am 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 that I used to buy the “SK40 Mandrel with a 7:24 taper” and there were no problems, but now I bought the “same” SK40, and suddenly doesn't fit." Let's try to understand the situation.

The customer is both right and wrong. The main problem lies in the designation itself. The letters SK indicate only the taper of the mandrel shank and are short for the German Steilkegel - steep taper. In this case, steep taper refers to mandrels with a 7:24 taper. Thus, by specifying SK when ordering, the customer determines only the type of shank. Other common types of shanks in the machine tool industry are the short hollow taper HSK, Morse taper MK, modular systems KM and Capto. The number 40 indicates the shank size. In this part, the reserve indicated everything correctly. His mistake is that in addition to the type and size of the shank, it is necessary to indicate the standard by which the shank is made.
In the USSR there was GOST 25827-83 “Tool shanks with a 7:24 cone.” 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 became fully compliant with the ISO 7388/1-83 standard. The “new” GOST was assigned a new Russian number - GOST R 50071-92. At the same time, I was completely “lost” old GOST 1983, resulting in another revision in 1993. It was decided to return the old, familiar number GOST 25827, and the Russian GOST R 50071-92 (which was issued “to replace GOST 25827-83 and GOST 24644-81 regarding 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 cone” in force.
This GOST standardizes three designs of shanks:

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

This is all in our country. What is the situation abroad?
Today in Europe the most common shanks are designed according to DIN - the German standard on the basis of which it was created international standard ISO. On Japanese machines, shanks with the MAS BT design (Japanese standard JIS B 6339) predominate. Machines with spindles according to this standard are becoming increasingly widespread in Europe, and accordingly, the range of auxiliary tools with this type of connection is expanding. In America, auxiliary tools with CAT/ANSI shanks are common. Some companies manufacture machines with spindle attachments of their own design (for example, Mazak). What are the fundamental differences between these shanks? 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). This standard has three versions:

• 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 for the grip of the manipulator.

The “AD” shape is similar to the “A” shape, only with a through central hole.
Execution “B” is structurally different among different companies, but the functions remain unchanged.
Execution 1 according to GOST 25827-93 (for manual tool changing) today fully complies with DIN 2080.
Many machines of domestic and Western production today are oriented specifically to DIN (ISO), less common are machines with a spindle design for MAS VT. Most companies producing auxiliary tools (including Russian ones) offer a full range of both standards.
When purchasing a machine, it is still better to once again clarify which spindle design is offered to the customer. Often machine tool manufacturers indicate only the standard size of the auxiliary tool without indicating to what standard the spindle is made. If you have a choice, it is better to choose a machine with an auxiliary tool that is already used in your enterprise. If a company offers, without an alternative, a machine with a type of spindle that has not previously been used in your production, it is better to contact the company offering the appropriate auxiliary tool and find out from it how wide the range of tools of this standard is available. Otherwise, you will have to search for a long time for a source to purchase the necessary auxiliary tools.
With all the variety of the considered auxiliary tools, there is partial interchangeability. All tools of the same standard size have the same base diameter and approximately the same base length. Most often, difficulty arises only during automatic tool changing, when the mandrel is taken from the machine magazine by the manipulator. Tools of different standards have different shape and the dimensions of the groove for the grip of the manipulator, as well as different distances from the base plane of the spindle to the axis of the groove. When changing manually, 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 this machine, or whether it is necessary to make a special transition rod. It is with the help of adapter rods that the auxiliary tool, made in accordance with DIN 69871, can be mounted on a machine with a spindle in accordance with GOST 25897-93 version 3. It is also recommended to check the basic length of the cone, since it also differs slightly between different standards.

And execution.

Morse taper and metric taper

Morse taper is one of the most widely used tool mounts. It was proposed by Stephen A. Morse around 1864.

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

Metric cone

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

There are no design differences between the Morse taper and the metric taper.

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

Table 1

	Cone designation	Taper	D	D 1	d	d 1	d 2	d 3 max	d 4 max	d 5	l 1 max	l 2 max	l 3 max	l 4 max	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

Shortened Morse tapers

For many applications, the length of the Morse cone turned out to be excessive. Therefore, nine standard sizes of shortened Morse cones were invented, obtained by removing the thicker part of the Morse cone. The number in the short cone designation is the diameter of the new thick part of the cone in mm. Russian standard for shortened 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.