UNF fine thread chart

24 sizes · ThreadRef · free sample of 8 representative sizes

UNF fine thread chart. The Unified fine series with threads per inch, major, pitch and minor diameters and tap drills in inches and millimetres - the companion sheet to the UNC chart.
Size	TPI	Major dia in	Pitch dia in	Minor dia in	Tap drill in	Tap drill mm	Hex A/F
#10-32 UNF	32	0.19	0.1697	0.1562	0.159	4.04	not defined
1/4-28 UNF	28	0.25	0.2268	0.2113	0.213	5.41	7/16"
5/16-24 UNF	24	0.3125	0.2854	0.2674	0.272	6.91	1/2"
3/8-24 UNF	24	0.375	0.3479	0.3299	0.332	8.43	9/16"
7/16-20 UNF	20	0.4375	0.405	0.3834	0.3906	9.92	5/8"
1/2-20 UNF	20	0.5	0.4675	0.4459	0.4531	11.51	3/4"
5/8-18 UNF	18	0.625	0.5889	0.5649	0.5781	14.68	15/16"
3/4-16 UNF	16	0.75	0.7094	0.6823	0.6875	17.46	1-1/8"

Dimensions per ASME B1.1 (Unified inch screw threads); wrench sizes per ASME B18.2.1.

Torque figures are estimates that depend on the stated nut-factor assumption. Verify against your fastener manufacturer's data and joint requirements before assembly.

Every figure on this chart is also free on its own size page - tap any size in the first column to open it, or browse the full reference. Premium pays for the sheet, not the numbers.