Machining Tungsten Alloys as per ASTM B777-15

(Also known as Mallory 1000®, Densalloy®, Fansteel 77® and Densimet®)

tungsten alloy machining guide

Tungsten Alloys, in addition to their high density, radiation shielding and vibration absorption characteristics can be machined using standard tools and equipment.  These alloys can be drilled, milled, turned, and tapped using speeds and feeds similar to Grey Cast Iron.  Parameters and tooling to accomplish proper machining are listed below.


• C-2 grade carbide tooling is recommended. Use as generous a nose radius as possible.


• Turning/Boring:  Positive rake is recommended
• Roughing:  0.050"/ 0.200" Depth of Cut: 0.008"/.010" Feed
• Finishing: 0.010"/0.030" Depth of Cut: 0.003"/0.005" Feed
• Turning Speed:  250/350 Surface feet per minute
• Note: For above operations, air is the preferred method of cooling tools; coolant can be used.


• Drilling: Use carbide tipped or solid carbide drills with air or coolant such as Molydisulfide (Moly-Dee) cutting fluid. Drill tap holes to 50-55% of thread hole requirement.
• Tapping: Use straight flute, high alloy taps. For small thread holes, thread forming taps can be used. Nitrided or solid carbide taps will extend life of tap on long run jobs.


• Use Aluminum Oxide type wheels ("J" grade typical) with coolant to remove grinding material rapidly.


• Feeds and Speeds: Follow Grey Cast Iron recommendations.
• Feeds:  0.003" per tooth as a starting point.
• Speed: 75 - 750 sfpm with carbide tools; adjust to depth of cut.
• End Milling:  Slight "climb" is best starting point.

Exotic Operations

• Wire EDM; Solid EDM; Waterjet Cutting can be performed on Tungsten Alloys.

Note: Applications specifically suggested for material described herein are made solely for the purpose of illustration to enable the reader to make his/her own evaluation. Guidelines are not intended as warranties, either expressed or implied, or fitness for these or other purposes. The data presented are typical of average values for all metal removal operations. They are not a guarantee of minimum or maximum values. Due to the distinguishing characteristics of each project, some metal/alloys may require adjustments (+/-) of speeds and/or feed which should be performed in small steps. Each job has to be developed for best production results with optimum tool life.