Item # TCTSBT02500XXX, Thread Cutting Tapping Screws Type BT, with 0.2500" Nominal Dia. On Sales Systems Ltd.

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.

Unit of Measure

Manufacturer | Specifications | Codes and Standards | Threads Per Inch

N/A Industrial Fasteners Institute

Product	N/A Tapping Screws
Unit of Measure	N/A English
Nominal Size or Basic Screw Dia.	N/A 1/4 in
Nominal Size or Basic Screw Dia. (Decimal)	N/A 0.2500 in
Max. Major Dia. (D)	N/A 0.246 in
Min. Major Dia. (D)	N/A 0.237 in
Max. Minor Dia. (d)	N/A 0.192 in
Min. Minor Dia. (d)	N/A 0.185 in
Ref. Point Dia. (P)	N/A 0.179 in
Max. Point Taper Length (S)	N/A 0.143 in
Min. Point Taper Length (S)	N/A 0.107 in
Min. Practical Nominal Screw Lengths for 90º Heads (L)	N/A 3/8 in
Min. Practical Nominal Screw Lengths for Csk Heads (L)	N/A 1/2 in

N/A ASME B18.6.4 1998

N/A 14

Manufacturer