Dorman Exhaust Stud Kits: Imperial vs Metric Sizes

A replacement exhaust-manifold or flange stud needs the correct thread standard, pitch, length and nut fit. Dorman kits 03112, 03113, 03131 and 03133 have different dimensions despite doing a similar job. Match the original hardware and the vehicle's service information before choosing a part.

Choose the thread standard before the length

The imperial 3/8-16 and metric M10 × 1.5 hardware are not interchangeable. Check both the thread diameter and pitch, not only whether the stud appears to enter the opening.

Exact Dorman stud MPN comparison

These are steel exhaust hardware kits. The store records identify hex-nut hardware and the washer information shown above. Verify the actual contents on the individual listing, particularly if the original assembly uses a specific spacer or washer.

What to check before replacing exhaust studs

1. Identify the original location: Determine whether the stud is used at the manifold, collector, flange or another exhaust joint. Compare its original equipment part number when available.
2. Match the thread: Use a thread gauge or manufacturer specifications to distinguish 3/8-16 from M10 × 1.5.
3. Measure usable length: Compare total length, installed thread engagement and required projection through the flange or nut.
4. Inspect the mating parts: Look for damaged female threads, corrosion and warped flanges. A replacement stud does not correct those issues by itself.
5. Use the correct installation procedure: Work only with a cool exhaust, use the specified torque and any approved anti-seize or thread-locking guidance, and check for exhaust leaks after assembly.

Questions about exhaust stud sizing

Are 03112 and 03113 the same except for length? The listed thread is 3/8-16 on both, but the stud lengths differ. Confirm all dimensions and hardware details before substituting.

Can an M10 × 1.5 stud replace a 3/8-16 stud? No. They are different thread specifications; forcing a mismatched stud can damage the threaded mounting hole.

Does Dorman 03133 include the same washer as 03131? The store records list a washer with 03131 but not with 03133. Check the item package and the vehicle's installation requirements.

Shop by exact exhaust stud part number

These four product cards link to the separate Dorman listings in our catalog. Check current item condition, availability and kit contents before ordering. The pictures are catalog images, not photographs establishing an individual item's condition.

Dorman 03112 · 3/8-16 × 2½-in exhaust stud kit

3/8-16 UNC thread; 2½ in stud length. Listed with washer.

Check product details and condition

Dorman 03113 · 3/8-16 × 3¼-in exhaust stud kit

3/8-16 UNC thread; 3¼ in stud length. Listed with washer.

Check product details and condition

Dorman 03131 · M10 × 1.5 × 71-mm exhaust stud kit

M10 × 1.5 thread; 71 mm stud length. Listed with washer.

Check product details and condition

Dorman 03133 · M10 × 1.5 × 62-mm exhaust stud kit

M10 × 1.5 thread; 62 mm stud length. No washer listed.

Check product details and condition

Other engine-service references

If your repair also involves engine starter positioning, compare our Dorman GM starter shim guide. Starter shims and exhaust studs are unrelated replacement parts with different service requirements.