A T-slot nut is chosen by the slot, not by the thread: DIN 650 fixes the slot widths a machine table may have, DIN 508 fixes which thread goes with each width, and the extrusion makers fix their own slots at 6, 8 and 10 mm. A slot that was cut to a metric width nobody standardised, a nut that must be longer to spread the load, or a thread the pairing does not allow is a T-nut that gets milled.
EKINSUN LTD is a custom parts manufacturer that mills T-slot nuts, profile nuts and T-bolts to drawing: an odd slot width, a long T-nut, a thread the DIN pairing skips, a stainless or brass nut for a slot that stock only fills in steel. The slot table below is DIN 508 as written; the profile table is what the extrusion market actually uses; the negative-space table marks where the catalogue ends.
"The rotary table has 16 mm slots. DIN 508 jumps from 14 to 18 and every T-nut I buy rocks in the slot."
Sixteen is not in the series; the nut is milled to sixteen.
| Slot width (DIN 650) | Thread (DIN 508) | Stock T-nut | T-bolt DIN 787 |
|---|---|---|---|
| 6 mm | M5 | class 10 steel | M5 |
| 8 mm | M6 | class 10 steel | M6 |
| 10 mm | M8 | class 10 steel | M8 |
| 12 mm | M10 | class 10 steel | M10 |
| 14 mm | M12 | class 10 steel | M12 |
| 18 mm | M16 | class 10 steel | M16 to order |
| 22 mm | M20 | class 10 steel | to order |
| 28 mm | M24 | to order | to order |
| 36 mm | M30 | to order | to order |
Stock DIN 508 T-nuts run M6–M20 in class 10 black steel; DIN 787 T-bolts M5–M12 in stock, M8 in stainless. Slot widths 5, 42, 48 and 54 mm exist in DIN 650 and are made to order.
| Type | Extrusion slot | Stock threads | Stock materials | Notes |
|---|---|---|---|---|
| Sliding T-nut (slide-in) | 6 mm (20 series), 8 mm (30 / 40 series), 10 mm (40 / 45 series) | M3–M8 | zinc and nickel steel; 304 | enters from the profile end |
| Hammer-head (drop-in) nut | 6, 8, 10 mm | M4–M8 | nickel steel | drops in and turns 90°; no end access needed |
| Spring-loaded T-nut (leaf spring) | 6, 8, 10 mm | M4–M8 | nickel steel | spring holds it in place while the screw is started |
| Spring-ball T-nut | 8, 10 mm | M4–M8 | nickel steel | ball detent instead of a leaf |
| Rhombus (diamond) nut | 8, 10 mm | M4–M8 | steel | rotates into the slot; for retrofits |
| Single-point spring nut (national standard) | 8, 10 mm | M4–M8 | nickel steel | one spring, one screw |
| Sliding block nut | 6–10 mm | M3–M8 | steel | long block for two screws |
| Type | Standard | Stock range | Stock materials | Notes |
|---|---|---|---|---|
| Square nut | DIN 557 | M3–M12 | 304; zinc and yellow-zinc steel M3–M10; black 304 M3–M13 | welded, captive or slid into channels |
| Thin square nut | DIN 562 | M3–M8 | 304 | for thin channels |
| Square weld nut | DIN 928 | M3–M24 | 304; plain steel | see weld nuts |
| T-head bolt (hammer-head) | DIN 186 / DIN 261 forms | M5–M12; M8 | 304; blue-zinc and nickel steel | the bolt that turns into a channel |
| T-bolt for extrusions | maker series | M5–M8 | 304; steel | for 8 and 10 mm slots |
| Square head bolt | DIN 478 / DIN 479 | M4–M12 | 304 | see square head bolts |
Read the pitch before you order the T-bolt. Lay a steel rule along ten thread crests and divide by ten: 10 mm over ten pitches is a 1 mm pitch (M6 coarse), 12.5 mm is M8 coarse, 15 mm is M10 coarse, 17.5 mm is M12 coarse. A reading that is not a round number of millimetres is an inch thread, and a reading that is shorter than the coarse pitch for that diameter is a fine thread. If diameter, pitch and the size range in the table all agree, buy the stock part. If any of the three is off the shelf, that is the one we make. The full measuring routine, including the inch traps →
| What you need | In the catalogue? | What we make |
|---|---|---|
| DIN 508 T-nut M6–M20 for a DIN 650 slot, class 10 steel | Yes | Buy it from stock. No one-off competes with a forged DIN 508 nut. |
| Profile nut M3–M8 for a 6, 8 or 10 mm extrusion slot, steel or 304 | Yes | Stocked; buy it from the profile supplier. |
| A T-nut for a slot width outside DIN 650 — 16, 20, 25 mm, or an inch slot | No | Milled from bar to the three slot dimensions you measure; from 1 piece. |
| A T-nut with a thread the DIN pairing does not give — M8 in a 14 mm slot, M12 in a 22 mm slot, or a fine pitch | No | Milled and tapped to the thread you need. |
| A long T-nut for two screws, or a T-nut with a dowel hole | No | Milled to length; holes drilled and reamed. |
| A DIN 508 nut in 304 / 316L stainless or in brass | No | Milled from stainless or brass bar; class 10 steel only in stock. |
| Profile nuts for a slot the extrusion maker has stopped producing | No | Measured from the profile and milled. |
| A T-nut in aluminium 6061 or 7075 | Partly | Milled on request for light jigs; 7075 takes more preload than 6061, and neither replaces class 10 steel on a machine table. |
| Material | Designation | Where it fits here |
|---|---|---|
| Carbon steel class 10, black | quenched and tempered | stock DIN 508 T-nuts and T-bolts |
| Alloy steel | 42CrMo4 / 1.7225 | milled T-nuts for machine tables outside the series |
| Stainless 304 | 1.4301 / A2 | stock profile nuts and square nuts; milled T-nuts for washdown frames |
| Stainless 316L | 1.4404 / A4 | milled to order for marine and chemical frames |
| Free-machining stainless | 303 / 1.4305 | custom milled profile nuts |
| Brass | CW614N / C36000 | milled T-nuts for electrical fixtures |
| Aluminium 6061 | AlMg1SiCu | milled light T-nuts for jigs and fixtures |
| Aluminium 7075 | AlZn5.5MgCu | milled where a light nut must carry more preload |
DIN 508 pairs a 12 mm slot with an M10 thread; the nut body is milled to the slot, and the thread is what the standard assigns. If you need M8 or M12 in a 12 mm slot, the nut is milled to order with that thread.
A sliding nut enters from the end of the extrusion; a hammer-head (drop-in) nut is inserted through the slot opening and turned 90 degrees, so it can be added to a frame that is already built. Spring-loaded and spring-ball nuts are drop-in nuts that hold themselves in place.
Yes. A 16, 20 or 25 mm slot, an inch slot, or a worn slot is measured across the top, at the shoulder and underneath, and the nut is milled from bar to those three numbers, from 1 piece.
Profile nuts and square nuts are stocked in 304. DIN 508 machine-table nuts are stocked in class 10 steel only; stainless or brass versions are milled to order.
EKINSUN LTD is a custom parts manufacturer that mills T-slot nuts, profile nuts, square nuts and T-bolts in alloy steel, 304 and 316L stainless, brass and aluminium, to any slot and any thread, from 1 piece, with a quote within 12 hours.
No list price. The drivers are material, the milling of the T profile, the thread, length and quantity. A single steel T-nut for an odd slot is a short milling job priced as one part; a batch of stainless long T-nuts with dowel holes is priced by the features. The quote states which.
Slot width at the top, at the shoulder and underneath, slot depth, thread and pitch, nut length, material, quantity. A photo of the slot with a caliper is enough. From 1 piece, quote within 12 hours.
T-slot nuts, profile nuts and T-bolts milled to your slot and thread — from 1 piece, quote in 12 hours.