Standard No.:	GB/T 70.2-2015
English Name:	Hexagon socket button head screws
Chinese Name:	内六角平圆头螺钉
Chinese Classification:	J13    Fastener
Professional Classification:	GB    National Standard
ICS Classification:	21.060.10 21.060.10    Bolts, screws, studs 21.060.10
Source Content Issued by:	AQSIQ;SAC
Issued on:	2015-12-10
Implemented on:	2017-1-1
Status:	to be superseded
Superseded by:	GB/T 70.2-2025 Fasteners - Hexagon socket screws - Part 2: Hexagon socket button head screws with reduced loadability
Superseded on:	2026-2-1
Abolished on:	2026-02-01
Superseding:	GB/T 70.2-2008 Hexagon socket button head screws
Target Language:	English
File Format:	PDF
Word Count:	300 words
Translation Price(USD):	60.0
Delivery:	via email in 1 business day

GB/T 70 series national standard includes: - GB/T 70.1 Hexagon Socket Head Cap Screws; - GB/T 70.2 Hexagon Socket Button Head Screws; - GB/T 70.3 Hexagon Socket Countersunk Head Screws; - GB/T 70.4 Hexagon Socket Button Head Screws with Collar; - GB/T 5281 Hexagon Socket Head Shoulder Screws This Part is the Part 2 of GB/T 70. ... ... ... ... 1 Scope This Part of GB/T 70 specifies the type dimension, technical requirement and marking of hexagon socket button head screws from M3 up to and including M16, with performance levels 08.8, 010.9, 012.9, 012.9, A2-070, A2-080, A3-070, A3-080, A4-070, A4-080, A5-070 and A5-080, product grade A and with reduced loadability according to Table 3. This Part is applicable to hexagon socket button head screws screwed in thread within engine body with internal hexagonal wrench. 2 Normative References The following documents for the application of this Standard are essential. Any dated reference, just dated edition applies to this Standard. For undated references, the latest edition (including any amendments) applies. GB/T 2 Fasteners - Ends of Parts with External Thread (GB/T 2-2001, idt ISO 4753: 1999) GB/T 70.5 Gauging of Hexagon Sockets (GWT 70.5-2008, ISO 23429:2004, IDT) GB/T 90.1 Fasteners-Acceptance Inspection (GB/T 90.1-2002, idt ISO 3269: 2000) GB/T 90.2 Fasteners - Marking and Packaging GB/T 193 General Purpose Metric Screw Threads - General Plan (GB/T 193-2003, ISO 261: 1998, MOD) GB/T 1237 System for Fasteners (GB/T 1237-2000, eqv ISO 8991: 1986) GB/T 3098.1 Mechanical Properties of Fasteners - Bolts, Screws and Studs (GB/T 3098.6-2000, ISO 898-1: 2009, MOD) GB/T 3098.6 Mechanical Properties of Fasteners - Stainless Steel Bolts, Screws and Studs (GB/T, 3098.6-2014, ISO 3506-1:2009, MOD) GB/T 3103.1 Tolerances for Fasteners - Bolts, Screws, Studs and Nuts (GB/T 3103.1-2002, ISO 4759-1: 2000, IDT) GB/T 5267.1 Fasteners - Electroplated Coatings (GB/T 5267.1-2002, ISO 4042: 1999, IDT) GB/T 5267.2 Fasteners - Non-Electrolytically Applied Zinc Flake Coatings (GB/T 5267.2-2002, ISO 10683: 2000, IDT) GB/T 5267.4 Passivation of Corrosion-Resistant Stainless-Steel Fasteners (GB/T 5267.4-2009, ISO 16048: 2003, IDT) GB/T 5276 Fasteners; Bolts, Screws, Studs and Nuts; Symbols and Designations of Dimensions (GB/T, 5276-1985, eqv ISO 225: 1983) GB/T 5779.1 Fasteners - Surface Discontinuities - Bolts, Screws and Studs for General Requirements (GB/T 5779.1-2000, idt ISO 6157-1:1988) GB/T 5779.3 Fasteners - Surface Discontinuities - Bolts, Screws And Studs for Special Requirements (GB/T 5779.3-2000, idt ISO 6157-3: 1988) GB/T 9145 General Purpose Metric Screw Threads - Limits of Sizes for the Screw Threads of Coarse Quality and Preferable Plan (GB/T, 9145-2003, ISO 965-2: 1998, MOD) GB/T 16938 Fasteners - General Requirements for Blots, Screws, Studs and Nuts (GB/T 16938-2008, ISO 8992: 2005, IDT) 3 Dimensions See Figures 1 and 2 for the type dimensions of screws.

Foreword I 1 Scope 2 Normative References 3 Dimensions 4 Technical Requirements and Referenced Standards 5 Marking