TYPES BF AND BT

4SMS_TAPPING_SCREW/TYPES BF AND BT-katsuhana
Product Name : TYPES BF AND BT
Product Introduction

TYPES BF AND BT

Table 8 Dimensions of Threads and Points for Types BF and BT Thread Cutting Tapping Screws

proimages/katsuhanan-products/4SMS_TAPPING_SCREW/3-THREAD CUTTING TAPPING SCREWS-TYPES BF AND BT.png
Nominal Size or Basic Screw Diameter Threads per lnch D d P S L
Major Diameter Minor Diameter Point Diameter Point Taper Length Minimum Practical Nominal Screw Lengths
Max Min Max Min Ref Max Min 90° Heads Csk Heads
0 0.0600 48 0.060 0.054 0.036 0.033 0.031 0.042 0.031 1/8 1/8
1 0.0730 42 0.075 0.069 0.049 0.046 0.044 0.048 0.036 1/8 5/32
2 0.0860 32 0.088 0.082 0.064 0.060 0.058 0.062 0.047 5/32 3/16
3 0.0990 28 0.101 0.095 0.075 0.071 0.068 0.071 0.054 3/16 7/32
4 0.1120 24 0.114 0.108 0.086 0.082 0.079 0.083 0.063 3/16 1/4
5 0.1250 20 0.130 0.123 0.094 0.090 0.087 0.100 0.075 7/32 9/32
6 0.1380 20 0.139 0.132 0.104 0.099 0.095 0.100 0.075 1/4 9/32
7 0.1510 19 0.154 0.147 0.115 0.109 0.105 0.105 0.079 1/4 5/16
8 0.1640 18 0.166 0.159 0.122 0.116 0.112 0.111 0.083 9/32 11/32
10 0.1900 16 0.189 0.182 0.141 0.135 0.130 0.125 0.094 5/16 3/8
12 0.2160 14 0.215 0.208 0.164 0.157 0.152 0.143 0.107 11/32 7/16
1/4 0.2500 14 0.246 0.237 0.192 0.185 0.179 0.143 0.107 3/8 1/2
5/16 0.3125 12 0.315 0.306 0.244 0.236 0.230 0.167 0.125 15/32 19/32
3/8 0.3750 12 0.380 0.371 0.309 0.299 0.293 0.167 0.125 17/32 11/16
7/16 0.4375 10 0.440 0.429 0.359 0.349 0.343 0.200 0.150 5/8 25/32
1/2 0.5000 10 0.504 0.493 0.423 0.413 0.407 0.200 0.150 11/16 27/32
See Notes 3

NOTES :

  1. Points of screws shall be tapered and fluted or slotted as illustrated above for the respective types. The flute on Type BT screws shall have an included angle of 90° to 95° and the thread cutting edge located above the axis of screw. Tapered threads shall have unfinished crests, and the flutes or slots shall extend through first full form thread beyond taper except for Type BF screws on which tapered threads may be complete at manufacturer’s option and flutes may be one pitch short of first full form thread. Other details of taper and flute design shall be optional with manufacturer, provided the screws meet the specified performance requirements.
  2. The width of flat at crest of thread shall not exceed 0.004 in. for sizes up to and including No. 8, and 0.006 in. for larger sizes.
  3. Where specifying nominal size in decimals, zeros preceding decimal and in the fourth decimal place shall be omitted.
  4. For additional requirements, see lntroductory Notes and General Data, page H-13 and page H-18.

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