Print Back
  • 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 90º to 95º 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 screw son 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.
  • 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.
  • Where specifying nominal size in decimals, zeros preceding decimal and in the fourth decimal place shall be omitted.
Types BT
Detail of Thread Form
Unit of Measure
1 

Item #

Description

Nominal Size or Basic Screw Dia.

Threads Per Inch

Max. (D)

Max. (d)

Ref. (P)

Max. (S)

TCTSBT00600XXX N/A Thread Cutting Tapping Screws Type BT, with 0.0600" Nominal Dia. N/A No. 0 N/A 48 N/A 0.060 in N/A 0.036 in N/A 0.031 in N/A 0.042 in
TCTSBT00730XXX N/A Thread Cutting Tapping Screws Type BT, with 0.0730" Nominal Dia. N/A No. 1 N/A 42 N/A 0.075 in N/A 0.049 in N/A 0.044 in N/A 0.048 in
TCTSBT00860XXX N/A Thread Cutting Tapping Screws Type BT, with 0.0860" Nominal Dia. N/A No. 2 N/A 32 N/A 0.088 in N/A 0.064 in N/A 0.058 in N/A 0.062 in
TCTSBT00990XXX N/A Thread Cutting Tapping Screws Type BT, with 0.0990" Nominal Dia. N/A No. 3 N/A 28 N/A 0.101 in N/A 0.075 in N/A 0.068 in N/A 0.071 in
TCTSBT01120XXX N/A Thread Cutting Tapping Screws Type BT, with 0.1120" Nominal Dia. N/A No. 4 N/A 24 N/A 0.114 in N/A 0.086 in N/A 0.079 in N/A 0.083 in
TCTSBT01250XXX N/A Thread Cutting Tapping Screws Type BT, with 0.1250" Nominal Dia. N/A No. 5 N/A 20 N/A 0.130 in N/A 0.094 in N/A 0.087 in N/A 0.100 in
TCTSBT01380XXX N/A Thread Cutting Tapping Screws Type BT, with 0.1380" Nominal Dia. N/A No. 6 N/A 20 N/A 0.139 in N/A 0.104 in N/A 0.095 in N/A 0.100 in
TCTSBT01510XXX N/A Thread Cutting Tapping Screws Type BT, with 0.1510" Nominal Dia. N/A No. 7 N/A 19 N/A 0.154 in N/A 0.115 in N/A 0.105 in N/A 0.105 in
TCTSBT01640XXX N/A Thread Cutting Tapping Screws Type BT, with 0.1640" Nominal Dia. N/A No. 8 N/A 18 N/A 0.166 in N/A 0.122 in N/A 0.112 in N/A 0.111 in
TCTSBT01900XXX N/A Thread Cutting Tapping Screws Type BT, with 0.1900" Nominal Dia. N/A No. 10 N/A 16 N/A 0.189 in N/A 0.141 in N/A 0.130 in N/A 0.125 in
TCTSBT02160XXX N/A Thread Cutting Tapping Screws Type BT, with 0.2160" Nominal Dia. N/A No. 12 N/A 14 N/A 0.215 in N/A 0.164 in N/A 0.152 in N/A 0.143 in
TCTSBT02500XXX N/A Thread Cutting Tapping Screws Type BT, with 0.2500" Nominal Dia. N/A 1/4 in N/A 14 N/A 0.246 in N/A 0.192 in N/A 0.179 in N/A 0.143 in
TCTSBT03125XXX N/A Thread Cutting Tapping Screws Type BT, with 0.3125" Nominal Dia. N/A 5/16 in N/A 12 N/A 0.315 in N/A 0.244 in N/A 0.230 in N/A 0.167 in
TCTSBT03750XXX N/A Thread Cutting Tapping Screws Type BT, with 0.3750" Nominal Dia. N/A 3/8 in N/A 12 N/A 0.38 in N/A 0.309 in N/A 0.293 in N/A 0.167 in
TCTSBT04375XXX N/A Thread Cutting Tapping Screws Type BT, with 0.4375" Nominal Dia. N/A 7/16 in N/A 10 N/A 0.44 in N/A 0.359 in N/A 0.343 in N/A 0.200 in
TCTSBT05000XXX N/A Thread Cutting Tapping Screws Type BT, with 0.5000" Nominal Dia. N/A 1/2 in N/A 10 N/A 0.504 in N/A 0.423 in N/A 0.407 in N/A 0.200 in
Unit of Measure
1