Type 25 Thread Cutting
Self tapping Screw Thread

Type 25 Thread Cutting Self-Tapping Screw Thread Dimensions
ANSI B18.6.4

Basic Screw Diameter or Nominal Size		Threads Per Inch	D		d		P	S		L		Minimum Torsional Strength (Lb In)
			Major Diameter		Minor Diameter		Point Dia	Point Taper Length		Minimum Practical Screw Length
			Max	Min	Max	Min	Ref	Max	Min	90° Heads	Csk Heads
2	.0860	32	.088	.082	.064	.060	.058	.062	.047	5/32	3/16	4
4	.1120	24	.114	.108	.086	.082	.079	.083	.063	3/16	1/4	13
5	.1250	20	.130	.123	.094	.090	.087	.100	.075	7/32	9/32	18
6	.1380	20	.139	.132	.104	.099	.095	.100	.075	1/4	9/32	24
8	.1640	18	.166	.159	.122	.116	.112	.111	.083	9/32	11/32	39
10	.1900	16	.189	.182	.141	.135	.130	.125	.094	5/16	3/8	56
12	.2160	14	.215	.208	.164	.157	.152	.143	.107	11/32	7/16	88
1/4	.2500	14	.246	.237	.192	.185	.179	.143	.107	3/8	1/2	142
5/16	.3125	12	.315	.306	.244	.239	.230	.167	.125	15/32	19/32	290
3/8	.3750	12	.380	.371	.309	.299	.293	.167	.125	17/32	11/16	590
Length Tolerance: Up to/including 3/4" = -.03, Over 3/4" = -.05

Applications For molded or through holes in plasticsand other soft materials. Excellent chip clearing.
Material Steel: AISI 1016-1024 oe equivalent steel
Heat Treatment Quenched in liquid and then tempered by reheating to 650°F minimum
Surface Hardness Rockwell C45 Minimum
Case Depth Nos. 4 thru 6 Dia. - .002-.007, Nos. 8 thru 12 dia. - .004 - .009, 1/4" and larger - .005 - .011
Core Hardness Rockwell C28 - C38 after tempering
Plating See plating pages