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Carbon		0.26 - 0.36
Chromium		3 - 3.75
Iron		Balance
Manganese		0.15 - 0.4
Phosphorus		0.03 max
Silicon		0.15 - 0.5
Sulphur		0.03 max
Tungsten		8.5 - 10
Vanadium		0.3 - 0.6

Principal Design Features		This alloy is one of the Hot Work, tungsten containing tool steels. The tungsten content is beneficial for hot strength at red heat, although toughness is somewhat reduced.

Applications		Used for hot working dies and tooling such as die casting, extrusion and hot forming of parts.

Machinability		The tungsten content makes H21 somewhat difficult to machine. As compared to the W group of water hardening low alloy steels rated at 100& for machinability the H21 would rate 55%

Forming		The alloy may be formed by conventional means.

Welding		This alloy may be welded. Consult the supplier for details.

Heat Treatment		Preheat to 1500 F and then heat rapidly to 2150 F. Hold at 2150 F for 2 to 5 minutes and then air cool (quench) or oil quench.

Forging		Forge at 2100 f down to 1700 F. Do not forge below 1650 F.

Hot Working		See "Forging".

Cold Working		H21 may be cold worked by conventional methods.

Annealing		Anneal at 1625 F and slow furnace cool at less than 40 F per hour.

Aging		Not applicable to this alloy.

Tempering		Tempering is done at 1100 F to 1250 F for Rockwell C hardness of 54 to 36. A double temper treatment should be done at the temperature selected and the parts should be held at temperature for 1 hour.

Hardening		See "Heat Treating" and "Tempering".

Physical Data : [top]

Density (lb / cu. in.)	0.296
Specific Gravity	8.2
Melting Point (Deg F)	2610
Modulus of Elasticity Tension	29

MSO currently has no data available for this grade.