Cutting speeds chart

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Starting points for turning on a rigid lathe. Hobby-size lathes: start at the low end. Figures marked EST are estimates not yet confirmed against a published source.

Material	HSS m/min	HSS SFM	Carbide m/min	Carbide SFM
Free-cutting steel	30–45 EST	98–148	150–250 EST	492–820
Mild / low-carbon steel	27–40	89–131	120–180	394–591
Medium-carbon steel (EN8 / A105 / LF2 class)	21–30	69–98	105–150	344–492
Alloy / Cr-Mo steel, annealed or normalised (≤ ~250 HB)	15–24	49–79	90–135	295–443
Alloy steel, hardened & tempered (~250–350 HB, e.g. EN24T)	9–15 EST	30–49	70–110 EST	230–361
Tool steel, annealed	12–21	39–69	60–107	197–351
Free-machining austenitic stainless (303)	20–30 EST	66–98	110–170 EST	361–558
Austenitic stainless (304 / 316 / 321)	11–21	36–69	70–120	230–394
Super-austenitic 6Mo stainless (254 SMO / AL-6XN / F44)	18–23	59–75	60–100 EST	197–328
Lean duplex stainless (LDX 2101 / 2304)	20–30	66–98	170–240	558–787
Duplex stainless 2205 (F51 / F60 / 1.4462)	15–20	49–66	90–160	295–525
Super duplex (2507 / Zeron 100 / F53 / F55)	10–15	33–49	50–105	164–344
Precipitation-hardening stainless (17-4PH / 15-5PH)	18–24	59–79	100–180 EST	328–591
Cast iron	18–27	59–89	76–137	249–449
Aluminium, wrought	75–180	246–591	180–450	591–1476
Aluminium, cast (silicon alloys)	60–120 EST	197–394	150–300 EST	492–984
Brass (free-cutting)	60–105	197–344	150–300	492–984
Bronze & gunmetal	30–60	98–197	90–180	295–591
Copper	45–75	148–246	120–240	394–787
Engineering plastics	60–150 EST	197–492	100–300 EST	328–984
Nickel-copper (Alloy 400 / K-500)	18–21	59–69	155–205	509–673
Ni-Fe-Cr / Ni-Cr solution alloys (Alloy 600 / 825)	8–11	26–36	40–70 EST	131–230
Ni-Cr-Mo corrosion alloys (Alloy 625 / C-276 / C-22)	6–6	20–20	30–55 EST	98–180
Age-hardened nickel superalloys (718 / Waspaloy / Nimonic 80A)	6–12	20–39	35–45	115–148
Titanium, commercially pure	18–30 EST	59–98	46–76	151–249
Titanium alloy (Ti-6Al-4V)	9–12	30–39	30–60	98–197
Cobalt-chrome / Stellite type alloys	–	–	10–30	33–98
Tungsten heavy alloy / copper-tungsten	–	–	61–122	200–400
Hardened steel 40–50 HRC	–	–	80–140	262–459

Spindle speed (rev/min) = 1000 × Vc ÷ (π × D)

Diameter	20 m/min	30 m/min	50 m/min	80 m/min	120 m/min	200 m/min
6 mm	1061	1592	2653	4244	6366	10610
10 mm	637	955	1592	2546	3820	6366
12 mm	531	796	1326	2122	3183	5305
16 mm	398	597	995	1592	2387	3979
20 mm	318	477	796	1273	1910	3183
25 mm	255	382	637	1019	1528	2546
30 mm	212	318	531	849	1273	2122
40 mm	159	239	398	637	955	1592
50 mm	127	191	318	509	764	1273
75 mm	85	127	212	340	509	849
100 mm	64	95	159	255	382	637

lathecalculator.co.uk – free to print and share for personal/workshop use. Values are for reference only – check against your tooling maker’s data.