Tapping Speed

Tapping Speed Chart

Surface Ft		5	10	15	20	25	30	35	40	50	60	70	80	90	100	120	130	150
Tap Size		Revolutions per Minute (RPM)
0	.0600	318	637	955	1275	1590	1910	2230	2545	3185	3820	4455	5095	5790	6365	7640	8275	9550
1	.0730	261	523	785	1045	1310	1570	1830	2095	2615	3140	3665	4135	4710	5230	6280	6800	7850
2	.0860	222	444	665	890	1110	1330	1555	1775	2220	2665	3110	3555	3995	4440	5330	5776	6660
3	.0990	193	385	580	770	965	1155	1350	1545	1930	2315	2700	3090	3470	3860	4630	5015	5790
4	.1120	171	341	510	630	850	1025	1195	1365	1705	2045	2390	2730	3070	3410	4090	4435	5415
5	.1250	153	306	460	610	765	915	1070	1220	1530	1835	2140	2445	2750	3055	3665	3970	4585
6	.1380	138	276	415	555	690	830	970	1105	1385	1660	1935	2315	2490	2765	3320	3595	4150
8	.1640	116	233	350	465	580	700	815	930	1165	1395	1630	1865	2095	2330	2795	3030	3495
10	.1900	100	201	300	400	500	605	705	805	1005	1205	1405	1610	1810	2010	2410	2615	3015
12	.2160	88	177	265	355	440	530	620	705	885	1060	1240	1415	1590	1770	2120	2300	2650
1/4	.2500	76	153	230	305	380	460	535	610	765	915	1070	1220	1375	1530	1835	1985	2230
5/16	.3125	61	122	185	245	305	365	425	490	610	735	855	980	1100	1220	1465	1590	1835
3/8	.3750	51	102	155	205	255	305	355	410	510	610	715	815	915	1020	1220	1325	1530
7/16	.4375	44	87	130	175	220	260	305	350	435	525	610	700	785	875	1050	1135	1310
1/2	.5000	38	76	115	155	190	230	270	305	380	460	535	610	690	765	915	995	1145
9/16	.5625	34	68	100	135	170	205	240	270	340	405	475	545	610	680	815	885	1020
5/8	.6250	31	61	90	125	155	185	215	245	305	365	430	490	550	610	735	795	915
3/4	.7500	25	51	75	100	125	155	180	205	255	305	355	410	460	510	610	660	765
7/8	.8750	23	44	66	87	109	131	153	175	219	262	306	349	392	438	526	585	655
1	1.0000	19	38	57	76	95	115	134	153	191	229	267	306	344	382	458	497	573
Pipe Tap Size
1/8		47	94	141	189	236	282	329	384	470	565	660	752	847	942	1130	1222	1410
1/4		35	71	106	141	177	212	248	283	354	425	495	566	638	708	850	921	1062
3/8		28	57	85	113	141	170	198	227	284	340	395	455	512	567	682	740	850
1/2		23	45	68	91	114	136	159	182	227	272	318	363	409	455	548	592	682
3/4		18	36	55	73	91	109	127	145	182	218	255	291	327	374	437	473	556
1"		15	29	44	58	73	88	102	116	145	175	204	233	262	292	350	378	436
1 1/4		12	23	35	46	58	70	81	93	115	138	162	185	208	231	277	300	347
1 1/2		10	20	30	40	50	60	70	80	100	120	140	160	180	200	241	262	302
2"		8	16	24	32	40	48	56	64	80	96	112	128	145	161	193	209	241

Formula: RPM = (3.82 × Surface feet per Minute)/ Diameter

Metric sizes — apply the formula

Metalforming taps (Jarflós) may be run at 1 1/2 to 2 times faster than cutting taps.

Suggested Tap Cutting Speeds

Material	Hardness (HB)	Condition	Threads per inch
Material	Hardness (HB)	Condition	8-15	16-24	26-up
			Surface Feet per Minute
1108-1211 1212-1215 11L17-12L14	100-150 150-200 200-250	HR,A HR,A,N,CD N,CD	60 60 70	90 90 100	120 130 140
1006-1017 1018-1023 1024-1026 1513-1514	100-125 125-175 175-225 225-275	HR,A,N,CD HR,A,N,CD HR,N,CD CD	50 45 40 30	70 60 50 40	100 90 70 60
4130-4150 4340-6150 8630-8740	175-225 225-275 275-325	HR,A,N,CD N,CD,Q and T N,Q and T	40 30 15	50 40 25	70 60 40
300 Series 400 Series 440-501	135-185 185-275 275-325	A A,CD Q and T	40 30 15	50 40 25	70 60 40
15-5PH - 17-4PH PH13-8 - PH15-7	150-200 150-200	A A	20 20	30 30	50 50
A286	275-325	ST	10	15	25
Inco 625,718, X750 M252, Rene 41 Waspaloy	260-300 250-300 325-375	ST ST ST	8 8 6	12 12 8	15 15 10
Aluminum		CD,ST and A	100	150	200+
Titanium	300-350	A	10	15	20
Leaded Brass Brass, Bronze Beryllium Copper	100-150 150-200 200-250	A,CD A,CD A,CD	100 80 40	150 100 50	200 150 80

Condition:

A — Annealed
CD — Cold drawn
H — Precipitation hardened
HR — Hot rolled
N — Normalized
Q and T — Quenched and tempered
ST — Solution treated
ST and A — Solution treated and aged
HB — Brinell hardness number

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