Sales Systems Ltd. - Large Hex Head Tapping Screws

Where specifying nominal size in decimals, zeros preceding decimal and in the fourth decimal place shall be omitted.
Applicable to screw types as indicated by code symbols.
Type AB thread forming.
Types B and BP thread forming and Types BF and BT thread cutting.
Type C thread forming, Appendix; and Types D, F, G, and T thread cutting.
A slight rounding of all edges and corners of the hex surfaces of indented hex heads shall be permissible, provided the diameter of the bearing circle is equal to no less than 90% of the specified minimum width across flats dimension.
Unless otherwise specified by purchaser, regular hex heads shall be furnished, and both regular and large head styles may be of indented head, trimmed head, or fully upset head construction, at the option of manufacturer.
Dimensions across flats and across corners of the head shall be measured at the point of maximum metal. Taper of sides of hex (angle between one side and the axis) shall not exceed 2° or 0.004", whichever is greater, the specified width across flats being the large dimension.
The rounding due to lack of fill on all six corners of the head shall be reasonably uniform and the width across corners of the head shall be such that when a sharp ring having an inside diameter equal to the specified minimum width across corners is placed on the top and bottom of the head, the head shall protrude by an amount equal to, or greater than, the F value tabulated. See Appendix II for across corners gaging of hex heads.
Large hex head is intended for screw and washer assemblies - SEMS, as specified in ASME B18.1 and other applications requiring large bearing.

Regular and Large Hex Head Tapping Screws

Unit of Measure

Items	LHHTS00730XXX Large Hex Head Tapping Screw, with 0.0730" Nominal Dia.	LHHTS00860XXX Large Hex Head Tapping Screw, with 0.0860" Nominal Dia.	LHHTS00990XXX Large Hex Head Tapping Screw, with 0.0990" Nominal Dia.	LHHTS01120XXX Large Hex Head Tapping Screw, with 0.1120" Nominal Dia.	LHHTS01250XXX Large Hex Head Tapping Screw, with 0.1250" Nominal Dia.
Manufacturer	N/A Industrial Fasteners Institute
Product	N/A Tapping Screws
Codes and Standards	N/A Abstract of ASME B18.6.4 1998
Unit of Measure	N/A English
Nominal Size or Basic Screw Dia.	N/A No. 1	N/A No. 2	N/A No. 3	N/A No. 4	N/A No. 5
Nominal Size or Basic Screw Dia. (Decimal)	N/A 0.0730 in	N/A 0.0860 in	N/A 0.0990 in	N/A 0.1120 in	N/A 0.1250 in
Applicable to Screw Types¹	N/A 1 2 3	N/A 1 2 3	N/A 1 2 3	N/A 1 2 3 4	N/A 1 2 3 4
Max. Width Across Flats (A)	N/A	N/A	N/A	N/A 0.219 in	N/A 0.250 in
Min. Width Across Flats (A)	N/A	N/A	N/A	N/A 0.213 in	N/A 0.244 in
Min. Width Across Corners (W)	N/A	N/A	N/A	N/A 0.238 in	N/A 0.272 in
Max. Head Height (H)	N/A 0.044 in	N/A 0.050 in	N/A 0.055 in	N/A 0.060 in	N/A 0.070 in
Min. Head Height (H)	N/A 0.036 in	N/A 0.040 in	N/A 0.044 in	N/A 0.049 in	N/A 0.058 in
Min. Protrusion Beyond Gaging Ring (F)	N/A 0.022 in	N/A 0.024 in	N/A 0.026 in	N/A 0.029 in	N/A 0.035 in
¹ 1 = Circle, 2 = Diamond, 3 = Triangle, 4 = Square