Standard No.:	GB/T 18685-2017
Chinese Name:	普通螺纹搓制和滚制前的毛坯直径
English Name:	The blank diameters for rolling general purpose metric screw threads
Professional Classification:	J04 Basic standards and general methods
ICS Classification:	21.040.01 Screw threads in general
Issued by:
Issued on:	2017-09-29
Implemented on:	2018-04-01
Status:	VALID
Replace:	GB/T18685-2002 The bar diameters for rolling general purpose metric screw threads
Language:	English
File Format:	PDF
Word Count:	6000 words
Price(USD):	180 (USD)
Delivery:	via email in 1-3 business day

1 Scope

This standard specifies the blank diameters for rolling general purpose metric screw threads. The nominal diameter of general purpose metric screw threads ranges from 1mm to 52mm (the first and second series diameter; the maximum pitch is 4mm); there are five thread tolerances: 4h, 6h, 6g, 6f and 6e.

This standard is applicable to the general purpose metric screw threads of carbon steel and alloy steel materials processed with full-profile extrusion process.

Note: "Full-profile extrusion process" refers to the processing method in which the thread materials completely fill the thread bottom space of the cutting tool when the thread is extruded.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 971-2008 Thread rolling cylindrical dies
GB/T 972-2008 Thread rolling flat dies
GB/T 3934-2003 Specification of gauges for general purpose screw threads
GB/T 14791 Screw threads - Vocabulary

3 Terms and definitions

For the purpose of this document, the terms and definitions specified in GB/T 14791 apply.

4 Calculation formula of blank diameter

The calculation formula of blank diameters for rolling screw threads shall meet the requirements of Annex A.