Tap & Clearance Drill Chart

Tap drill sizes (≈75% thread), clearance holes and tensile stress areas. Metric per ISO 261/262, Unified per ASME B1.1.

Thread	Pitch / TPI	Tap drill	Clearance	Tensile area
M3	0.5 mm	2.5	3.4	5.03 mm²
M4	0.7 mm	3.3	4.5	8.78 mm²
M5	0.8 mm	4.2	5.5	14.2 mm²
M6	1 mm	5	6.6	20.1 mm²
M8	1.25 mm	6.8	9	36.6 mm²
M10	1.5 mm	8.5	11	58 mm²
M12	1.75 mm	10.2	13.5	84.3 mm²
M16	2 mm	14	17.5	157 mm²
M20	2.5 mm	17.5	22	245 mm²
#4-40	40 tpi	0.089 (#43)	0.116	0.00604 in²
#6-32	32 tpi	0.1065 (#36)	0.144	0.00909 in²
#8-32	32 tpi	0.136 (#29)	0.17	0.014 in²
#10-24	24 tpi	0.1495 (#25)	0.196	0.0175 in²
1/4-20	20 tpi	0.201 (#7)	0.266	0.0318 in²
5/16-18	18 tpi	0.257 (F)	0.328	0.0524 in²
3/8-16	16 tpi	0.3125 (5/16)	0.391	0.0775 in²
1/2-13	13 tpi	0.4219 (27/64)	0.531	0.1419 in²
5/8-11	11 tpi	0.5312 (17/32)	0.656	0.226 in²
3/4-10	10 tpi	0.6562 (21/32)	0.781	0.334 in²

Full interactive lookup: Thread & Fastener Reference.

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