Machining

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Recommended Tools and Machining Parameters Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys

Be aware that the cobalt-base alloys in these categories (25 and 188) can require different feeds and speeds (as noted in the table) than the nickel- and iron-based alloys.

Operations Tool Types Tool Geometryand Set-Up Speed Feed Depth of Cut Lubricant
- - - surface ft./min* in** in** -
Roughing with severe interruptions; Turning or Facing Carbide: C-2 or C-3grade
Negative rake square or trigon insert,  45° SCEA1, 1/16 in nose radius Tool holder: 5° negative back rake, 5° negative side rake
 30-50 0.004-0.008per revolution 0.15
Dry2, oil3, or water-based4,5
Normal roughing; Turning or Facing As above As above 
90 (80 for cobalt alloys)6
 0.010per revolution <0.15 Dry, oil, or water-based
Finishing; Turning or Facing As above 
Positive rake square or trigon insert, if possible, 45° SCEA1, 1/32 in nose radius Tool holder: 5° positive back rake, 5° positive side rake
 95-110 (90 for cobalt alloys) 0.005-0.007 per revolution 0.04 Dry or water-based
Rough Boring As Above If insert-type boring bar, use standard positive rake tools with largest possible SCEA and 1/16 in nose radius.  If brazed tool bar, grind 0° back rake, 10° positive side rake, 1/32 in nose radius and largest possible SCEA 70 (60 for cobalt alloys) 0.005-0.008 per revolution 0.125 Dry, oil, or water-based
Finish Boring As Above Use standard positive rake tools on insert-type bars. Grind brazed bars as for finish turning, except back rake may be best at 0° 95-110 (90 for cobalt alloys) 0.002-0.004 per revolution 0.04 Water-based
High Speed Steel: M-2, M-7, or M-40  series7
 Radial and axial rake0° to 10° positive, 45° corner angle, 10° relief angle 20-30 (20-25 for cobalt alloys) 0.003-0.005 per tooth - Oil or water-based
Carbide: C-2 grade (marginal performance) Use positive axial and radial rake, 45° corner angle, 10° relief angle 50-60 (35-40 for cobalt alloys) 0.005-0.008per tooth (0.005 per tooth for cobalt alloys) - Oil or water-based
End Milling High Speed Steel: M-40 series or T-15 If possible, use short mills with four or more flutes for rigidity 20-25 (15-20 for cobalt alloys) Feed per tooth: ¼ in dia. 0.002 ½ in dia. 0.002 ¾ in dia. 0.0031 in dia. 0.004(cobalt alloys: ¼ in dia. 0.001 ½ in dia. 0.0015 ¾ in dia. 0.0021 in dia. 0.003) - Oil or water-based
Carbide: C-2 grade  Use sharp tools with 4 or more flutes and variable lead, if possible Carbide: C-2 grade (marginal performance) Use positive axial and radial rake, 45° corner angle, 10° relief angle - Oil or water-based
Drilling High Speed Steel: M-33, M-40 series, or T-15 Use short, heavy-web drills with 135° crank shaft point; thinning of web at point may reduce thrust and aid chip control 10-15 (7-10 for cobalt alloys) Maximum of 200 rpm for¼ in dia. drills or smaller Feed per rev.: ⅛ in dia. 0.001 ¼ in dia. 0.002 ½ in dia. 0.003 ¾ in dia. 0.0051 in dia. 0.007(same for cobalt alloys)   - Oil or water-based Use coolant feed drills if possible
Carbide :C-2 grade  Not recommended, but tipped drills may be successful on rigid set-ups if depth is not great. The web must be thinned to reduce thrust; use 135° included angle on point Gun drill can be used. 50 (40 for cobalt alloys) As above - Oil or water-based Coolant-fed, carbide-tipped drills may be economical in some set-ups
Reaming High Speed Steel: M-33, M-40 series, or T-15 Use 45° corner angle, narrow primary land, and 10° relief angle 10-15 (8 for cobalt alloys) Feed per rev.: ½ in dia. 0.0032 in dia. 0.008 (same for cobalt alloys)   - Oil or water-based
Carbide: C-2 or C-3grade   Tipped reamers recommended; solid reamers require very good set-up. Tool geometry same as above. 40 (20 for cobalt alloys) As above - Oil or water-based
Tapping High Speed Steel: M-1, M-7, or M-10 Use two flute, spiral point, plug tap 0° to 10° hook angles. Nitrided surface may be helpful by increasing wear resistance, but may result in chipping orbreakage Tap drill for 60-65% thread if possible, to increase tool life. 7 (same for cobalt alloys) - - Use best possible tapping compound; sulfo-chlorinated oil-base preferred
Carbide: not recommended - - - - -
Electrical Discharge Machining HAYNES® and HASTELLOY® alloys can be readily cut using any conventional Electrical discharge machining (EDM) system, or by wire EDM

General note: Use high pressure coolant systems and through the tool coolant, when possible.

*To convert to surface m/min, multiply by 0.305
**To convert from in to mm, multiply by 25.4

1SCEA = side cutting edge angle, or lead angle of the tool
2At any point where dry cutting is recommended, an air jet directed at the tool may provide a substantial increase in tool life
3Oil coolants should be premium quality, sulfo-chlorinated oils, with extreme pressure additives; a viscosity of 50 to 125 SSU at 100°F (38°C) is standard
4Water-based coolants should consist of a 15:1 mixture of water and either a premium quality, sulfo-chlorinated, water-soluble oil or a chemical emulsion, with extreme pressure additives
5Water-based coolants may cause chipping or rapid failure of carbide tools in interrupted cuts
6Depending upon the rigidity of the set-up
7M-40 series high speed steels include M-41 through M-46 at time of writing; others may be added and should be equally suitable

Applicable to:
Wear & Corrosion-resistant Alloy

ULTIMET® alloy can be successfully turned, drilled, and milled if appropriate tooling and parameters are employed. However, the alloy possesses high strength and work hardens rapidly. Machining guidelines specific to ULTIMET® alloy are as follows:

Turning (ULTIMET® alloy)

Carbide (not high speed steel) tools are recommended.

Surface speed: 60-70 surface ft./min (0.30-0.35 m/s).

Feed rate: 0.005-0.010 in (0.13-0.25 mm).

Depth of cut for roughing: 0.05-0.10 in (1.3-2.5 mm).

Depth of cut for finishing: 0.010-0.015 in (0.25-0.38 mm).

Drilling (ULTIMET® alloy)

Carbide tipped or high speed steel drills are recommended.

Surface speed: 30-35 surface ft./min (0.15-0.18 m/s) for carbide tipped drills; 8-10 surface ft/min (0.04-0.05 m/s) for high speed steel drills.

Feed rate: 0.004 in (0.1 mm) per revolution for 0.25 in (6.4 mm) diameter and greater.

135° included angle on point.

Milling (ULTIMET® alloy)

Carbide (not high speed steel) end mills are recommended.

Surface speed: 25-30 surface ft/min (0.13-0.15 m/s).

Feed per tooth: 0.002 in (0.05 mm) for cutter diameters below 0.75 in (19 mm); 0.003 in (0.08 mm) for cutter diameters above 0.75 in (19 mm).

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