Screw Manufacturers & Screw Suppliers From Taiwan and China.

Hot Search: Flat Head Socket Head Cap Screw,Phillips Screw,Slotted Screw,Machine Screw,Button Head Socket Cap Screw,Socket Set Screw

Magaizne

Asia-Pacific Fastener News Magazine is a professional magazine which focuses on promoting Taiwanese & Chinese fasteners to global markets in the hardware Industry.

This magazine is a monthly issue in English. It contains information of updated global fastener news and latest information on Taiwanese & Chinese fastener manufacturers......

Thread Forming Tapping Screws
Thread Forming Tapping Screws
  • Products Name: Thread Forming Tapping Screws(TYPE AB)
  • High Quality Product
    Competitive Price
    Punctual Delivery
    Best Service Support

Products Infomation

An introduction: A 40 year evolution followed. It can be traced through four distinct phases of tapping screw design- thread forming, thread cutting, thread rolling and self-drilling.
I. Thread forming screw are Types AB,.B, BP A, and C. Type C, with its machine threads and high-driving torques became obsolete with the introduction of thread rolling screws. It is no longer recommended for new designs. The only difference between Types AB, B and BP is their point design. AB is a threaded gimlet, Type B has a blunt point, and Type BP has an unthreaded gimlet. Gimlet points center into preformed holes and facilitate thread start, but they are longer and need more blind side clearance. Also gimlet points tend to be a sharp and may damage other components in the assembly if they contact.
Table 6 Dimensions of Threads and Points For Type AB Thread Forming Tapping Screws

Nominal Size   or 

 Basic Screw Diameter

Threads per inch

D d L
Major Diameter Major Diameter Minimum Practical Screw Lengths
Max Min Max Min 90Heads Csk Heads
0 0.0600 48 0.060 0.054 0.036 0.033 1/8 5/32
1 0.0730 42 0.075 0.069 0.049 0.046 5/32 3/16
2 0.0860 32 0.088 0.082 0.064 0.060 3/16 7/32
3 0.0990 28 0.101 0.095 0.075 0.071 3/16 1/4
4 0.1120 24 0.114 0.108 0.086 0.082 7/32 9/32
5 0.1250 20 0.130 0.123 0.094 0.090 1/4 5/16
6 0.1380 20 0.139 0.132 0.104 0.099 9/32 11/32
7 0.1510 19 0.154 0.147 0.115 0.109 5/16 3/8
8 0.1640 18 0.166 0.159 0.122 0.116 5/16 3/8
10 0.1900 16 0.189 0.182 0.141 0.135 3/8 7/16
12 0.2160 14 0.215 0.208 0.164 0.157 7/16 17/32
1/4 0.2500 14 0.246 0.237 0.192 0.185 1/2 19/32
5/16 0.3125 12 0.315 0.306 0.244 0.236 5/8 3/4
3/8 0.3750 12 0.380 0.371 0.309 0.299 3/4 29/32
7/16 0.4375 10 0.440 0.429 0.359 0.349 7/8 1 1/32
1/2 0.5000 10 0.504 0.493 0.423 0.413 1 1 5/32
See Notes 3,4

NOTES:
1. No extrusion of excess metal beyond apex of the point resuiting from thread rolling shall be permissible a slight rounding or truncation of the point is desirable.
2. The width of flat at crest of thread shall not exceed 0.004 inch for sizes up to and including No.8,and 0.006 inch for larger sizes.
3. Where specifying nominal size in decimals,zeros preceding decimal and in the fourth decimal place shall be omitted.
4. Sizes shown in bold type are prefrred.
5. For determining the effective grip of screws see Appdx . Vll , page H-58.
6. For additional requirements , see introductiry Notes and General Data , page H-11.

About Us | Terms and Conditions|Legal Policy|Privacy Policy|Useful Links|Contact Us

Copyright © 2011 Screw007.com All rights reserved.