EKINSUN is a custom parts manufacturer that makes pins to drawing: a spring pin in a length or diameter the series skips, a grooved pin with your groove pattern, a split pin or R-clip in 316L, a linch pin for a specific shaft, a knurled pin for a worn hole. The size ranges are those a distributor stocked in 2026.
A typical request: 6 mm spring pins, 52 mm long, stainless, where the catalogue has 50 and 55 and the 55 sticks out into the gear.
Length between the steps is the usual reason a pin is made; an inch hole is the next.
Pin types and size ranges
| Type | Standard | Size range | Common materials | Notes |
|---|---|---|---|---|
| Slotted spring pin, heavy | ISO 8752 / DIN 1481 | 1.5–16 mm | spring steel black; 304 M1.5–M12 | the general-purpose spring pin, and the one sold as a roll pin across North America, same part, same ISO 8752 dimensions; slot along the length |
| Slotted spring pin, light | ISO 13337 / DIN 7346 | on request | spring steel | thinner wall for soft materials |
| Coiled spring pin | ISO 8750 (standard), ISO 8748 (heavy), ISO 8751 (light) | on request | spring steel; stainless | a rolled spiral; more uniform spring, kinder to the hole |
| Split (cotter) pin | ISO 1234 / DIN 94 | 1–12 mm | 304 M1–M8; white-zinc steel 1.5–12 mm | bent over after fitting; single use |
| R-clip (spring cotter, hairpin) | DIN 11024 | 1–5 mm wire | 304; zinc steel 1–2 mm | snaps over a shaft; reusable |
| Linch pin | DIN 11023 | on request | zinc steel | a pin with its own captive ring |
| Grooved pins | DIN 1470 (parallel grooves), 1471 (taper), 1472 (half-length taper), 1473 (parallel with pilot), 1474 (half-length reverse), 1475 (centre), 1476 (round head), 1477 (countersunk head) | 1.5–8 mm knurled | steel; 304 | three grooves displace metal; press fit in a drilled hole |
| Knurled pin | maker series | 1.5–8 mm | 304 | knurl instead of grooves; repairs a worn hole |
| Toggle (flip) pin | maker series | M8–M20 | 304 | a pin with a swivelling stop |
| Clevis and grooved clevis pins | ISO 2341 / DIN 1444 | 3–20 mm | 304 | see clevis pins |
| Dowel and taper pins | ISO 8734, ISO 2338, ISO 2339 | 1.5–30 mm | steel; 304 | see dowel pins and taper pins |
Need spring pins, cotter pins and R-clips in a size, thread or material no catalogue lists? EKINSUN is a custom parts manufacturer: we make spring pins, cotter pins and R-clips to your drawing, sketch or sample, spring steel, 304 or 316L stainless steel, from 1 piece, quoted in 12 hours and shipped duties paid. Standard sizes can often be supplied from stock; the more pieces, the lower the unit price. All custom fasteners
Which pin wants which hole
| Pin | Hole | How it holds | Reusable |
|---|---|---|---|
| Slotted spring pin | drilled to the nominal size with a loose tolerance (the standards use H12); no reaming | the tube compresses and springs against the hole | yes, with some loss of spring |
| Coiled spring pin | drilled, as above | the spiral compresses evenly; lower insertion force | yes |
| Grooved pin | drilled to the nominal size | the grooves' raised edges displace into the hole wall | not normally |
| Knurled pin | drilled; oversize holes tolerated | the knurl displaces into the wall | no |
| Dowel pin | reamed to a fit (H7 / m6 or p6) | interference or transition fit | yes |
| Split pin | drilled cross-hole; loose | legs bent over the shaft end | no; replace |
| R-clip | drilled cross-hole; loose | the spring loop grips the shaft | yes |
The reason to choose a spring pin over a dowel is the hole: a drilled hole is a fraction of the cost of a reamed one and a spring pin forgives a worn or slightly oversize hole that would let a dowel walk. The reason to choose a dowel is location: a spring pin locates to a drilled hole, a dowel to a reamed one; see the dowel pin size chart for the fits.
What to send for a pin that is not standard
- Pin type, or the job: locating, hinging, shear, retaining a nut or a clevis.
- Diameter and length; for a spring pin the hole diameter it goes into; for a grooved pin the groove type.
- Material: spring steel for plain duty, 304 for corrosion, 316L for chemical, brass or beryllium copper for non-sparking.
- The shear load if the pin carries one, so the wall or the section is sized.
- Quantity; a single pin for a machine is a normal order.
Where the pin catalogue stops
| What you need | In the catalogue? | What we make |
|---|---|---|
| Slotted spring pin ISO 8752 1.5–16 mm, split pin ISO 1234 1–12 mm, R-clip DIN 11024, standard length | Yes | Buy it from stock, or have it made to order from 1 piece. No one-off competes with a rolled spring pin or a formed split pin. Standard parts: ask us too, we may have them in stock. |
| Grooved and knurled pins 1.5–8 mm, clevis pins 3–20 mm | Yes | Standard sizes: buy them off the shelf, or have them made to order from 1 piece. Standard parts: ask us too, we may have them in stock. |
| A spring pin in a length between the standard steps, or above 16 mm diameter | No | Rolled or machined to length and diameter, from 1 piece. |
| A pin for an inch hole, or a pin with a diameter between metric sizes | No | Made to the hole you measure. |
| A grooved pin with your own groove pattern, a head, a pilot or a shoulder | No | Turned and grooved to drawing. |
| A split pin, R-clip or linch pin in 316L, brass or beryllium copper | No | Formed in the material named. |
| A solid pin with a cross-hole, a groove for a circlip, a flat or a thread | No | Turned to drawing, see pivot pins and clevis pins. |
| A spring pin in aluminium 6061 or 7075 | No | Not offered: aluminium has no spring and a soft pin shears; we quote a stainless or steel pin, or a turned 7075 solid pin for a reamed hole, and say why. |
Materials
| Material | Designation | Where it fits here |
|---|---|---|
| Spring steel | 65Mn, C67S, C75S; black oxide or zinc | standard spring pins, R-clips, wire clips |
| Stainless spring steel | 1.4310 / 301; 304 / 1.4301 | standard stainless spring pins, split pins, R-clips |
| Stainless 316L | 1.4404 / A4 | formed pins and clips to order for chemical and marine duty |
| Carbon steel, zinc | low-carbon | standard split pins, linch pins |
| Alloy steel | 42CrMo4 / 1.7225 | turned solid pins with grooves and cross-holes |
| Brass, beryllium copper | CW614N, CuBe2 | non-sparking and non-magnetic pins to order |
| Aluminium 6061 | AlMg1SiCu | the housing the pin goes into; not a spring pin material |
| Aluminium 7075 | AlZn5.5MgCu | turned solid pins for reamed holes in light assemblies |
Related pages
- the nut, bolt, washer and pin chart, all families with standard and size range
- Dowel pins, pins for reamed holes
- Dowel pin size chart, fits and tolerances
- Taper pins, 1:50 taper pins
- Clevis pins, pins with a split-pin hole
- Pivot pins, hinge pins with circlip grooves
- retaining rings, circlips and E-clips
- Castle nuts, the nut a split pin locks
Frequently asked questions
Yes. Roll pin is the common North American name for a slotted spring pin, ISO 8752 / DIN 1481. There is no dimensional difference: the same 1.5–16 mm sizes, the same rolled tube, the same drilled hole. Coiled spring pins ISO 8750 are also sold as roll pins by some distributors, so if the pin matters, say slotted or coiled rather than relying on the name.
A spring pin is a rolled tube that compresses into a drilled hole and holds by its own spring, so the hole needs no reaming and a worn hole is forgiven. A dowel pin is a solid ground pin that needs a reamed hole and locates precisely. Spring pins fasten; dowels locate.
The nominal pin diameter, drilled, with the loose tolerance the standard allows (H12 in the ISO 8752 and ISO 8750 tables). The pin's outside diameter is larger than nominal and compresses on entry; there is no reaming.
Slotted (ISO 8752) is the general-purpose, lower-cost pin with a single slot. Coiled (ISO 8750) is a rolled spiral that compresses evenly, inserts with less force and is kinder to soft or thin-walled parts; it is the better choice for repeated assembly and for aluminium housings.
Yes. Spring pins, grooved pins, split pins and R-clips in lengths between the standard steps, in diameters for inch holes, and in 304, 316L, brass or beryllium copper are made from 1 piece.
EKINSUN is a custom parts manufacturer that makes spring, grooved, knurled, split, clevis, pivot and solid pins to drawing in spring steel, 304 / 316L stainless, alloy steel, brass and beryllium copper, from 1 piece, with a quote within 12 hours.
No list price; the drivers are material, the process (rolling, turning, grooving), features and quantity. A batch of stainless spring pins cut to an odd length is a short job; a single turned pin with grooves, a cross-hole and a thread is priced as the machined part it is. The quote names the drivers.
Send the hole and the length
Pin type or job, diameter, length, hole size, material, shear load if any, quantity. A photo of the old pin on a rule works. From 1 piece, quote within 12 hours.