The difference between metric shoulder screws and ANSI shoulder screws:

Metric shoulder screws, which is fit metric thread shoulder screw, and is ANSI shoulder screw in accordance with the ANSI thread. The outer diameter and the pitch of the shoulder thread can also be measured with a caliper. The outside diameter of the metric shoulder screw is in millimeters, such as 4 mm,6 mm,8 mm,10 mm,12 mm, etc. The pitch is also in millimeters, such as 0.5 mm, 0.75 mm,1 mm, 1.5 mm,2 mm,3 mm, and so on. The outside diameter of the thread shoulder screw is in inches (25.4 mm per inch), such as 3/16 inch,5/8 inch,1/ 4 inch, etc., or # 2 # 4 # 6 # 8 # 10, etc., so when measuring the outer diameter with a metric caliper, the reading is often with irregular decimal numbers.

Tolerance for metric shoulder screws, manufacturing tolerances based on the reference of M1~M6 upset shoulder screws, and the drawings shall be properly relaxed on this basis.

Minimum tolerance range (MM)  M1~M2     M2.5~M4     M5~M6 

Head diameter (free-forming)       ±0.1       ±0.2        ±0.2

Head diameter (sleeve forming)   ±0.05      ±0.1        ±0.1

Head thickness                                 ±0.1       ±0.15       ±0.2

Shoulder diameter                          ±0.05      ±0.08    ±0.08

Thread diameter                     by standard   by standard      by standard

Thread length                                   -0.2        -0.4         -0.5

Shenzhen Shi Shi Tong Metal Products Co., Ltd. is a professional shoulder screw manufacturing factory, welcome people from all walks of life to order metric shoulder screws and ANSI shoulder screws. Since it was put into production in 1998, tens of thousands of screws and related hardware fasteners have been produced.

Skype: kalyn qin M: +86 18124507113 Tel: +86 0755-85296744 Email: annie.li@szsst88.com Add: No. 11, Dinghou Road, Dongfang Community, Songgang Street, Baoan District, Shenzhen, Guangdong, China