This standard specifies the basic requirements for position tolerance, material and hardness, appearance and surface roughness, marking and packaging of straight shank reamer, Morse taper shank reamer and sleeve reamer. This standard applies to reamer produced in accordance with GB/T4256 and GB/T1142. GB/T 4257-2004 Technical conditions for reamer GB/T4257-2004 standard download decompression password: www.bzxz.net

ICS 25. 100, 30
National Standard of the People's Republic of China
GB/T4257—2004
Replaces GB/T4257--1984
Core drills-—Technical requirementsIssued on 2004-02-10
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of ChinaAdministration of Standardization of the People's Republic of China
Implementation on 2004-08-01
This standard replaces GB/T4257—1984 "Technical requirements for core drills" from the date of its implementation. Compared with GB/T4257-1984, this standard has the following changes: - The writing format is in accordance with GB/T1.1-2000;
- The material of the hole reamer is changed from \W18Cr4V\ to W6Mo5Cr4V2"; - The performance test chapter is cancelled;
- The surface roughness in the type size is included in this standard; - The mark is adjusted.
This standard is proposed by the China Machinery Industry Federation. This standard is proposed and managed by the National Tool Standardization Technical Committee. The drafting unit of this standard: Chengdu Measuring Tools and Cutting Tools Co., Ltd. The main drafter of this standard: Huang Huaxin.
Previous publications of the standards replaced by this standard: 7-1984.
GB/T 4257-
GB/T4257—2004
1 Scope
Bore reamer
Technical conditions
GB/T4257—2004
This standard specifies the basic requirements for position tolerance, material and hardness, appearance and surface roughness, marking and packaging of straight shank reamer, Morse taper shank reamer and sleeve reamer. This standard applies to reamer produced in accordance with GB/T4256 and GB/T1142. 2 Normative references
The following documents are used in this standard. The clauses of this standard are made by reference to the standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties that reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version applies to this standard. GB/T4256 Straight shank and Morse taper shank reamer (GB/T4256-2004, ISO7079:1981, MOD) GB/T1142 Shell reamer (GB/T1142-200 4, ISO3314:1975, MOD) 3 Position tolerance
The position tolerance of the reamer is shown in Table 1.
d≤18
The oblique circular runout of the cutting edge to the common axis The radial circular runout of the working part to the common axis 4 Diameter taper
d>18～30
The diameter taper of the working part of the reamer: 0.04mm~0.10mm for every 100mm length. 5 Material and hardness
The unit is mm
d>30～100
5.1 The reamer is made of W6Mo5Cr4V2 or other grades of high-speed steel with equivalent performance, and the welded shank is made of 45 steel or other grades of steel with equivalent performance.
5.2 Hardness of reamer:
-Working part: 63HRC~~66HRC;
Handle or flat tail: 40HRC~~55HRC for integral reamer, 30HRC~45HRC for welded reamer. 6 Appearance and surface roughness
6.1 The surface of the reamer shall not have defects such as cracks, scratches, rust and grinding burns that affect the performance. 6.2 The upper limit of surface roughness is:
Front and back: Rz6.3um;
Outer circle of the shank, surface of the cone hole of the sleeve reamer: Rao.8μm; Outer circle of the working part: Rz6.3μm.
GB/T 4257—2004
7 Marking and packaging
7.1 Marking
7.1.1 The product should be marked with:
The trademark of the manufacturer or seller;
-Basic diameter of the reamer;
High-speed steel code (HSS).
The packaging box should be marked with:
The name, address and trademark of the manufacturer or seller; the name, basic diameter and standard number of the product; the brand or code of the high-speed steel;
The number of pieces;www.bzxz.net
-Year and month of manufacturing.
7.2 Packaging
The reamer should be treated with rust prevention before packaging, and the packaging must be firm to prevent damage during transportation.
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