Machinability and machining of 321 stainless steel
The machinability of grade 321 stainless steel is 36% in annealed conditions based on a 100% machinability rating for 1212 steel.
| Rated speeds and feeds for turning a variety of steels and cast irons with single-point and high-speed steel (HSS) case tools | |||||||||
| Material | Hardness, HB | Illness | Cutting depth, mm (in.) | high speed steel tool | Tool material | ||||
| Speed | To feed | ||||||||
| m/min | sfm | mm/rotation | in./rev | ISO | AISI | ||||
| SS321 forged austenitic | 135-185 | Annealed | 1 (0.04) | 34 | 110 | 0.18 | 0.007 | S4, S5 | M2, M3 |
| 4 (0.15) | 27 | 90 | 0.4 | 0.015 | |||||
| 8 (0.30) | 21 | 70 | 0.5 | 0.02 | |||||
| 16 (0.625) | 17 | 55 | 0.75 | 0.03 | |||||
| Rated speeds and feeds for turning a variety of steels and cast irons with single-point and carbide-tipped case tools | ||||||||||||||||
| Material | Hardness, HB | Illness | Carbide Tool | |||||||||||||
| Uncoated | Coated | |||||||||||||||
| Speed | To feed | Tool material class | Speed | To feed | Tool material class | |||||||||||
| Soldier | Indexable | |||||||||||||||
| m/min | sfm | m/min | sfm | mm/rotation | in./rev | ISO | W | m/min | sfm | mm/rotation | in./rev | ISO | W | |||
| SS321 forged austenitic | 135-185 | Annealed | 105 | 350 | 120 | 400 | 0.18 | 0.007 | K01, M10 | C-3 | 160 | 525 | 0.18 | 0.007 | CK01, CM10 | CC-3 |
| 100 | 325 | 105 | 350 | 0.4 | 0.015 | 135 | 450 | 0.4 | 0.015 | |||||||
| 76 | 250 | 84 | 275 | 0.5 | 0.02 | C-2 | 105 | 350 | 0.5 | 0.02 | CC-2 | |||||
| 60 | 200 | 64 | 210 | 0.75 | 0.03 | K20, M20 | – | – | – | – | – | – | ||||
| Rated speeds and feeds for turning a variety of steels and cast irons with ceramic tools | ||||||||
| Material | Hardness, HB | Illness | Cutting depth, mm (in.) | Speed | To feed | Type of ceramic | ||
| m/min | sfm | mm/rotation | in./rev | |||||
| SS321 austenitic | 135-185 | Annealed | 1 (0.040) | 425 | 1400 | 0.13 | 0.005 | Cold pressed alumina |
| 4 (0.150) | 275 | 900 | 0.25 | 0.010 | ||||
| 8 (0.300) | 185 | 600 | 0.40 | 0.015 | ||||
| Rated speeds and feeds for turning a variety of steels and cast irons with high-speed steel and carbide cutting and forming tools | ||||||||||||||
| Material | Hardness, HB | Illness | Speed | Feed, mm/rev (in./rev) | Tool material class | |||||||||
| Cutting tool width | Form tool width | |||||||||||||
| m/min | sfm | 1.5 mm (0.062 in.) | 3 mm (0.125 in.) | 6 mm (0.250 in.) | 12 mm (0.500 in.) | 18 mm (0.750 in.) | 25 mm (1.00 in.) | 35 mm (1.50 in.) | 50 mm (2.00 in.) | ISO | AISI or C | |||
| SS321 austenitic | 135-185 | Annealed | 26 | 85 | 0.033 (0.0013) | 0.041 (0.0016) | 0.050 (0.002) | 0.050 (0.002) | 0.041 (0.0016) | 0.036 (0.0014) | 0.030 (0.0012) | 0.025 (0.001) | S4, S5, K40, M40 | M2, M3, C-2 |
| 84 | 275 | |||||||||||||
| Speeds and feeds for trepanning deep holes of various steels with high-speed tool steels and carbide tools | ||||||||
| Material | Hardness, HB | Illness | Speed | To feed | Tool material class | |||
| m/min | sfm | mm/rotation | in./rev | ISO | AISI or C | |||
| Austenitic: SS321 | 135-185 | Annealed | 20 | 65 | 0.075 | 0.003 | S4, S5 | M2, M3 |
| 84 | 275 | 0.15 | 0.006 | K20 | C-2 | |||
| 225-275 | Cold drawing | 18 | 60 | 0.075 | 0.003 | S4, S5 | M2, M3 | |
| 69 | 225 | 0.10 | 0.004 | K20 | C-2 | |||
| Nominal speeds for grinding ferrous alloy and carbide threads | |||||||||
| Material | Hardness, HB | Illness | Thread designation | ANSI Wheel Identification | Wheel speed | Working speed | |||
| Step, mm | Threads per 25 mm (1 in.) | IN | sfm | m/min | sfm | ||||
| Forged austenitic stainless steels: 321, 201, 202, 301, 302, 302B, 304, 304L, 305, 308, 309, 309S, 310, 310S, 314, 316, 316L, 317, 330, 347, 34 8, 3 84, 385 | 135-275 | Annealed or cold drawn | 6-2.5 | 4-12 | A90RB | 43 | 8,500 | 1.2 | 4.0 |
| 2-1 | 13-27 | A120SB | 46 | 9,000 | |||||
| 0.8-0.45 | 28-63 | A180TB | 48 | 9500 | |||||
| 0.4-0.35 | 64-80 | A220UB | 51 | 10,000 | |||||
| Recommended speeds and feeds for face milling of ferrous and non-ferrous alloys with high-speed steel and carbide cutters | |||||||||||||
| Material | Hardness, HB | Illness | Cutting depth, mm (in.) | high speed steel tool | Carbide Tool | ||||||||
| Uncoated | Coated | ||||||||||||
| Speed | Feed per tooth, mm (in.) | Tool material class, ISO (C) | Speed, m/min (sfm) | Feed per tooth, mm (in.) | Tool material class, ISO (C) | ||||||||
| Speed, m/min (sfm) | Feed per tooth, mm (in.) | Tool material, ISO (AISI) | Soldier, m/min (sfm) | Indexable, m/min (sfm) | |||||||||
| Forged Austenitic Stainless Steel 321 | 135-185 HB | Annealed | 1 (0.040) | 40 (130) | 0.20 (0.008) | S4, S2 (M2, M7) | 130 (430) | 145 (475) | 0.20 (0.008) | K10, M20 (C-2) | 215 (700) | 0.20 (0.008) | CK10, CM20 (CC-2) |
| 4 (0.150) | 30 (100) | 0.30 (0.012) | S4, S2 (M2, M7) | 100 (325) | 110 (360) | 0.30 (0.012) | K20, M30 (C-2) | 145 (475) | 0.30 (0.012) | CK20, CM30 (CC-2) | |||
| 8 (0.300) | 24 (80) | 0.40 (0.016) | S4, S2 (M2, M7) | 70 (230) | 85 (280) | 0.40 (0.016) | K30, M40 (C-2) | 105 (350) | 0.40 (0.016) | CK30, CM40 (CC-2) | |||
| Recommended speeds and feeds for milling plates (or flats) of ferrous and non-ferrous alloys with high-speed steel cutters | ||||||||
| Material | Hardness, HB | Illness | Cutting depth, mm (in.) | Speed | Feed per tooth | High speed steel tool material | ||
| m/min | sfm | mm (in.) | ISO | AISI | ||||
| Forged Austenitic Stainless Steel 321 | 135-185 HB | Annealed | 1 (0.040) | 55 | 180 | 0.15 (0.006) | S4, S2 | M2, M7 |
| 4 (0.150) | 43 | 140 | 0.20 (0.008) | |||||
| 8 (0.300) | 34 | 110 | 0.25 (0.010) | |||||
| Recommended speeds and feeds for end (peripheral) milling of ferrous and non-ferrous alloys with high-speed steel and carbide cutters |
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| Material | Hardness, HB | Illness | Radial depth of cut, mm (in.) | high speed steel tool | Carbide Tool | ||||||||||
| Speed, m/min (sfm) | Feed, mm/tooth (in./tooth), in cutter diameter of: | Tool material, ISO (AISI) | Speed, m/min (sfm) | Feed, mm/tooth (in./tooth), in cutter diameter of: | Tool material, ISO (C) | ||||||||||
| 10 mm (0.375 in.) | 12 mm (0.5 in.) | 18 mm (0.75 in.) | 25-50 mm (1-2 in.) | 10 mm (0.375 in.) | 12 mm (0.5 in.) | 18 mm (0.75 in.) | 25-50 mm (1-2 in.) | ||||||||
| SS321 | 135-185 HB) | Annealed | 0.5 (0.020) | 34 (110) | 0.025 (0.001) | 0.050 (0.002) | 0.102 (0.004) | 0.13 (0.005) | S4, S5, S2 (M2, M3, M7) | 110 (360) | 0.013 (0.0005) | 0.025 (0.001) | 0.050 (0.002) | 0.102 (0.004) | K20, M20 (C-2) |
| 1.5 (0.060) | 24 (80) | 0.050 (0.002) | 0.075 (0.003) | 0.13 (0.005) | 0.15 (0.006) | 82 (270) | 0.025 (0.001) | 0.050 (0.002) | 0.075 (0.003) | 0.13 (0.005) | |||||
| diam/4 diam/4 |
21 (70) | 0.025 (0.001) | 0.050 (0.002) | 0.102 (0.004) | 0.13 (0.005) | 72 (235) | 0.025 (0.001) | 0.038 (0.0015) | 0.063 (0.0025) | 0.102 (0.004) | |||||
| diam/2 diam/2 |
18 (60) | 0.025 (0.001) | 0.038 (0.0015) | 0.075 (0.003) | 0.102 (0.004) | 67 (220) | 0.013 (0.0005) | 0.025 (0.001) | 0.050 (0.002) | 0.075 (0.003) | |||||
