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T-Slot Stud Dimensions (DIN 6379, M6 to M24)

Guide · Updated October 28, 2026

DIN 6379 covers double-ended studs for use with DIN 508 T-slot nuts. The nut-end thread length, shank diameter d2 and stock lengths below agree across the Elesa+Ganter DIN 6379 sheet, the Dold Mechatronik DIN 6379 sheet and the J.W. Winco DIN 6379 sheet (Winco lists more lengths); the short-thread lengths for M6 to M24 also match the DIN 6379:2003 table extract. Skipped: M18, M22, M27, M30, M36 and M42 (only one source lists a full row). M14 is a catalog size that the standard sheet does not include. Check the current edition or your supplier for critical work.

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Step by step

  1. Match the T-nut: Pick the stud thread to match your DIN 508 T-nut: 14 mm slot with M12, 18 mm with M16, 22 mm with M20.
  2. Use the short end in the nut: The short thread end (9 mm on M6 up to 35 mm on M24) goes into the T-nut. It is sized to the DIN 508 nut height so the stud stops flush with the nut base and does not bottom on the slot floor.
  3. Check the shank: The plain middle shank d2 is about the thread minor diameter, so a strap clamp slides over it freely.
  4. Choose the length: Lengths are given as overall length l and top thread length, e.g. 80-50 = 80 mm long with 50 mm of thread on the clamping end.
  5. Stack the clamp: Nut height + clamp strap + DIN 6340 washer + DIN 6331 collar nut, plus 2 to 3 threads spare, sets the length you need above the T-nut.
  6. Tighten in the right order: Run the short end fully into the T-nut first, then set the strap and torque the top nut. Do not tighten against the slot floor.

DIN 6379 T-slot stud dimensions (mm)

Columns: thread d1, nut-end thread length (short end, into the T-nut), shank diameter d2, common lengths as overall length l - top thread length. Catalogs label the nut-end thread b2; the standard labels it b1.

* M14 is sold by catalogs but is not in the DIN 6379 standard sheet.

Worked example: M16 stud in an 18 mm slot

An 18 mm DIN 508 nut is M16 and 20 mm tall; the M16 stud's 19 mm nut end sits just inside it. Above the nut you need a 25 mm strap, a 4 mm washer and a 24 mm DIN 6331 collar nut, plus about 5 mm spare: 25 + 4 + 24 + 5 = 58 mm of top thread. The 100-63 stud gives 63 mm of top thread, so it fits; the 63-32 is too short.

DIN 6379 vs DIN 787 vs an all-thread rod

Common problems

FAQ

What is a DIN 6379 stud?

A double-ended threaded stud for machine-table clamping. One short thread end screws into a DIN 508 T-nut; the long end takes the strap clamp and a collar nut.

Why is one thread end so short?

The short end is sized to the height of the DIN 508 T-nut, so the stud cannot push through and bear on the slot floor. That would lift the nut and can crack the table.

What does 80-50 mean?

Overall length 80 mm with 50 mm of thread on the long (clamping) end.

Why is M14 marked?

Catalogs sell M14 studs, but the DIN 6379 standard sheet itself does not list M14.

Can I use a DIN 939 or DIN 938 stud instead?

Not recommended. Those studs have an interference-fit metal end whose length does not match T-nut height.

What strength are DIN 6379 studs?

The catalogs we checked list heat-treated steel, class 10.9 for M6 to M12 and 8.8 for M14 to M24; the standard itself calls for at least 8.8.

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General shop information only — follow your drawing, tool maker's data and your quality system.