Roll Pin vs. Dowel Pin vs. Spring Pin: What's the Difference

PIN TYPES · REFERENCE

"Roll pin," "spring pin," "slotted pin," "dowel pin" — these terms get used interchangeably, but they aren't all the same part, and grabbing the wrong one means a joint that won't hold or won't go together. Here's a plain breakdown of what each is and when to use it.

Spring pin / roll pin / slotted pin — the same family

These three names mostly describe one thing. A spring pin is a hollow, rolled-metal sleeve made slightly oversized for its hole. You drive it in; it compresses, then springs back against the bore walls to hold by friction and tension. The different names actually describe the three main features of the pin.

• "Slotted pin" is the formal engineering term. It has a slot down its length.
• "Roll pin" is the common shop name explains how it's made — it's rolled from sheet.
• "Spring pin" describes how it works — it acts as a spring against the hole.

For most shop purposes, roll pin = spring pin = slotted spring pin. (There's also a coiled spring pin — wound rather than rolled — used for heavier or more forgiving applications, but the slotted/rolled type is what most people mean.)

Use a roll pin when: you want a fast, self-retaining pin that absorbs shock and tolerates a less-than-perfect hole — hinges, linkages, handles, fixtures, general assembly.

Dowel pin — a different part entirely

A dowel pin is solid and precision-ground to a tight diameter. It does not compress. It's installed in a reamed hole as a slip or press fit and is used for precise alignment — locating two parts to each other with no play.

Use a dowel pin when: position accuracy matters — aligning mating plates, fixturing, tooling, anything where the pin sets exact location rather than just holding parts together.

Drift pin — not really a pin

A drift pin is a tapered tool, not a fastener. It's used to align holes in two parts so a bolt or rivet can pass through, or to drive other pins out. If a spec calls for a "drift pin," check whether it means the tapered alignment tool or is just loose shorthand — they're not interchangeable with roll or dowel pins.

Which do you need?

• Holding parts together, fast, forgiving? Roll / spring pin.
• Locating parts precisely, no play? Dowel pin.
• Aligning holes to pass a fastener? Drift (a tool).

If it's a roll/spring pin, getting the hole size right is what makes the difference between a clean install and a fight. Our Spring Pin & Roll Pin Size Chart lists nominal diameters and recommended hole sizes for every common size, and the B&M Pintool drives them in square without marring the part.