DIN 2510 Waisted Studs

A waisted stud has a thread on each end and a shank turned down to about the thread root diameter between them. Each end of the shank blends into the thread with a 20° taper and a radius, so there is no sharp step to concentrate stress.

Because the shank is thinner than the thread, the stud stretches along its full length when it is tightened. That extra elastic stretch helps the joint hold its preload through heat cycles, gasket relaxation and vibration, and it improves fatigue life. This is why DIN 2510 bolting is common on turbines, high-pressure valves, steam and process piping, and pressure vessel flanges.

Waisted studs are often tightened with hydraulic bolt tensioners. DIN 2510-2 gives the external thread a larger clearance for this kind of tightening and to help prevent seizing at high temperature.

DIN 2510 is a series of standards for bolted connections with reduced shank. Part 1 is the overview, part 2 the large-clearance thread, part 3 stud bolts, part 4 studs, part 5 hex nuts, part 6 cap nuts, part 7 extension sleeves and part 8 tapped holes.

DIN 2510-3 stud bolts come in several forms:

• Form L: longer thread length b1 on each end, for standard hex nuts.
• Form K: shorter thread length b2, about equal to the nominal diameter.
• Forms KU, Z and ZU: variants for other nut arrangements, including cap nuts on both ends.

Larger sizes in the standard add a heating bore through the stud so it can be heated for tightening. If your drawing calls for a form, size or feature not shown here, send it to us and we will quote to it.

Typical DIN 2510-3 dimensions in inches, converted from the metric values in the standard. Thread sizes keep their metric names, with the pitch shown as the equivalent threads per inch (TPI). The nominal length l1 is chosen to suit the joint. Form L is not listed for M56.

These values are for reference. Check them against the current edition of DIN 2510 and your drawing before ordering. You can draw any of these sizes to scale with our fastener drawing generator.

We make DIN 2510 studs in ASTM bolting grades that are readily available in the US, matched to the temperature and service of the joint:

• A193 B7 and B7M: chromium-molybdenum alloy steel for general high-temperature and high-pressure service
• A193 B16: chromium-molybdenum-vanadium alloy steel for higher-temperature service
• A320 L7 and L43: alloy steel for low-temperature service
• A453 660 (A-286): iron-nickel-chromium alloy for elevated-temperature service
• A193 B8 and B8M: austenitic stainless steel for corrosive service

Studs are marked with the manufacturer’s symbol and the ASTM grade symbol, such as B7 or B16. Tell us the grade your specification calls for and we will quote to it. Compare grades in our Fastener Materials Matrix.

A DIN 2510 stud bolt is designated by form, size, length and material grade, for example:

Stud bolt DIN 2510 – L M30 × 7.874 in – B7

That is a Form L stud, M30 thread, nominal length l1 of 7.874 in, in ASTM A193 B7. To quote, tell us:

• Form (L, K or other) and size, for example M36.
• Nominal length l1 in inches.
• Material and any marking requirements.
• Matching nuts, if you need them, and quantity.

If you have a drawing, upload it and we will make the studs to it. You can also build one with our drawing generator and send it straight to our team.