How to Specify Tungsten Heavy Alloy on a Drawing: ASTM B777, AMS 7725, MIL-T-21014

Which standard belongs in the material note when a drawing calls for tungsten heavy alloy? For a new part, cite ASTM B777 or SAE AMS 7725F. The MIL-T-21014 on older drawings was cancelled in 1998, and its SAE replacement was cancelled in 2008. The harder part is everything else a supplier has to read off the drawing: the class, magnetic or nonmagnetic, density, coatings, certificates and compliance language. This guide takes those decisions in order and ends with a sample note you can adapt.

The Four Specs at a Glance

The status comes from ASTM’s listing for B777-15(2026), SAE’s page for AMS7725F, and the withdrawal record for AMS-T-21014, which shows the Department of Defense dropped its adoption of that document effective April 13, 2012.

Step 1: Choose the Standard

Both documents cover four classes of tungsten heavy alloy, roughly 90 to 97 percent tungsten, made by pressing and sintering powder. ASTM B777 sets composition and mechanical properties. AMS 7725F covers the same material, and published supplier summaries say it asks for more: tighter control of manufacturing, testing and traceability, plus a sintered and annealed condition. One supplier’s comparison says B777 approves a powder lot once, while AMS 7725 tests each combination of powder lot and sintering lot. SAE sells the full text and we have not reproduced it, so read your own copy before you rely on a specific clause.

In practice the choice usually makes itself. For counterweights, ballast, shielding and general engineering work, cite ASTM B777. When a prime, a program office or a customer drawing already says AMS 7725F, cite that. Many drawings list one as the primary and the other as an alternate, for example “Tungsten heavy alloy, Class 1, per ASTM B777” with “Class 1, Type 2, per AMS 7725F” as the alternate. If you list both, say which one governs, and ask the supplier to confirm in writing which standard its certificate is against.

Our custom tungsten parts page lists alloy grades from 17.0 to 18.8 g/cm³ per ASTM B777 and AMS7725F. If your program needs full AMS 7725F lot testing, say so when you ask for a quote, so scope gets confirmed against your drawing before anyone commits to a price.

Step 2: Pick the Class

The class sets the tungsten content, and everything else follows from it: density goes up, and ductility comes down. These are the ASTM B777 requirements as we publish them on our technical data page.

Minimum yield is 517 MPa in every class. Class 2 is the usual starting point for counterweights and ballast. Move to Class 3 or 4 only when the part has room to be small and will not see shock or drop loads, because the extra density costs ductility. Our class-by-class breakdown goes through the trade-offs, and the weight arithmetic is in how to read a density number.

Step 3: Set Magnetic or Nonmagnetic

Heavy alloy is tungsten held together by a binder. A nickel-iron binder makes the alloy slightly magnetic. A nickel-copper binder makes it nonmagnetic. Classes 1 to 3 come in both. Class 4 does not: at 97 percent tungsten there is not enough binder left to hold the copper system together at production strength, so Class 4 is magnetic only. Nonmagnetic material also has a lower strength floor, 648 MPa minimum tensile against 758 or 724 for the standard grades.

If nonmagnetic matters, write it on the drawing and give the limit and the test. Typical reasons are MRI equipment, shipboard compasses and sensitive instruments. One supplier’s published summary defines nonmagnetic as a relative permeability of 1.05 or less, measured to ASTM A342. Confirm the number with your own engineering rather than copying it.

AMS 7725 states the same choice as a Type. Supplier tables read Type 1 as nonmagnetic and Type 2 as magnetic, but older revisions and some online databases label them differently, so check your copy of the standard. Do not leave it blank. One supplier’s summary says AMS 7725 supplies Class 1 and Type 2 when the drawing does not say.

Step 4: Add What the Standard Leaves Open

A standard tells a supplier how to make the material. It does not know what your part is for. These are the points that most often decide whether the part comes back the way you drew it.

• Where the properties are measured. ASTM B777 tests coupons, not finished parts, and the standard notes that sintered properties vary with part size and location. If a specific area of a large part has to meet a property, say so and agree on where it is tested.
• Density. B777 gives a range for each class. If weight is the whole point of the part, give a minimum density or a weight tolerance on the drawing.
• Condition. Say whether you want the material as sintered or sintered and annealed, since AMS 7725 treats them as separate conditions.
• Coatings. B777 covers bare and coated parts. Name the coating specification and thickness, and say whether the dimensions apply before or after coating.
• Tolerance and finish. Tolerance the features that matter and call out ground or lapped surfaces only where they are needed. Heavy alloy machines on its own parameters, as our machining guide explains, and every tight tolerance adds cost.
• Impact. If the part will be dropped, shocked or hit, stay in Class 1 or 2 whatever the density target says.

Step 5: Call Out Compliance and Certification

Ask for a Certificate of Conformance that names the standard and its revision, the class and type, the lot number, and the measured density and hardness. Add tensile if you need it. We provide a certificate of conformance and full lot traceability on every order, and a first-article inspection with dimensional and weight verification.

For defense work, name the clause and its scope instead of writing “DFARS compliant” alone. DFARS 252.225-7052 restricts tungsten melted or produced in a covered country through December 31, 2026. From January 1, 2027 it reaches tungsten mined, refined, separated, melted or produced there, and recycled material is part of that chain. The covered countries are China, Russia, Iran and North Korea. Get the country of melt in writing, and see what the clause covers and our sourcing verification checklist. Origin does not reset when material passes through a recycler, a point Tungsten Buyers explains from the scrap side.

If the drawing is export-controlled, say so before you send it. Tungsten Parts Wyoming is ITAR-registered.

Step 6: Clear Legacy MIL-T-21014 Callouts

MIL-T-21014D was cancelled by Notice 1 in 1998, with later acquisitions pointed to the SAE version, AMS-T-21014. SAE cancelled that in March 2008 and superseded it with ASTM B777, and the cancellation notice says the latest B777 applies wherever the old document is referenced. Neither belongs on a new drawing.

When you meet one on an existing drawing, do not assume the old class maps straight across. Read the old callout, find the matching row in the B777 table above, and have engineering confirm it. Then put ASTM B777 on the drawing at its next revision. If you are quoting the part before that, give the supplier the old callout and ask for a B777 equivalent in writing. You can see the original documents at EverySpec.

Step 7: Send a Complete RFQ Package

The fastest quotes come with the drawing as a PDF and a native file, the standard with its class and type, the quantity and delivery date, the certificate you need, the compliance clause and its scope, and any coating. In-stock standard sizes ship in 3 to 5 days. Custom runs take 10 to 12 weeks, depending on shape, size and quantity. Send it through our quote form.

If your drawing is a bucking bar or riveting tool instead of a counterweight or a machined part, our sister brand USA Tungsten builds custom bucking bars to a drawing or sample.

A Sample Drawing Note

This is an example to adapt, not a requirement. Brackets mean you choose.

MATERIAL: TUNGSTEN HEAVY ALLOY PER ASTM B777, CLASS 2, [MAGNETIC | NONMAGNETIC].
ALTERNATE: AMS 7725F, CLASS 2, TYPE [2 | 1].
DENSITY: 17.15 G/CM3 MIN. HARDNESS: 33 HRC MAX.
CONDITION: [AS SINTERED | SINTERED AND ANNEALED].
COATING: [NONE | PER SPEC ____, ____ MICRON, DIMENSIONS AFTER COATING].
CERTIFICATION: C OF C WITH LOT NUMBER, STANDARD AND REVISION, CLASS,
DENSITY AND HARDNESS. COUNTRY OF MELT PER DFARS 252.225-7052 SCOPE.

Frequently Asked Questions

What is AMS 7725F?

It is the SAE aerospace material specification for sintered tungsten heavy alloy shapes, revised in November 2020 and first issued in 1957. It covers four classes of the alloy and is the AMS counterpart to ASTM B777.

Is MIL-T-21014 still valid?

No. MIL-T-21014D was cancelled in 1998, and its SAE successor, AMS-T-21014, was cancelled in March 2008 and superseded by ASTM B777. Keep it only as a reference on legacy drawings and replace it at the next revision.

What is the difference between ASTM B777 and AMS 7725?

Both define four classes of the same alloy. ASTM B777 sets composition and mechanical properties. Supplier summaries say AMS 7725F adds tighter control of manufacturing, testing and traceability. Read the SAE text to see exactly what it requires.

What do Type 1 and Type 2 mean in AMS 7725?

Supplier tables treat Type 1 as nonmagnetic and Type 2 as magnetic. Older revisions and some databases label them differently, so confirm against your copy of the standard.

Can I cite both standards on one drawing?

Yes. Many drawings list one as the primary callout and the other as an alternate. Say which governs if they differ, and ask the supplier to confirm in writing which standard its certificate is against.

What should the certificate of conformance include?

The standard and its revision, the class and type, the lot number, and the measured density and hardness, plus tensile if you need it. For defense work add a country of melt statement that matches the scope of DFARS 252.225-7052 on your contract.

Tungsten Parts Wyoming manufactures tungsten and tungsten heavy alloy components, powder to finished part, in Laramie, Wyoming, under ISO 9001. Send us the drawing and we will confirm the class, tolerances and certification before we quote. Our tungsten heavy alloy page lists the grades.