Tips for Inserting a Roll Pinby Tom King
Roll pins are used in a variety of automotive and industrial applications to provide a clean, hidden method of connecting parts at 90 degrees, allowing the two parts to swivel in relation to one another. The roll pin mates two parts by passing through them. A groove in the pin allows the pin to collapse when inserted and then to spring back and hold itself in place. Roll pins are ideal for places where there isn't space for nuts and bolts or other fasteners.
Start with the proper tools. You'll need a soft-faced mallet, roll pin punch tool, a roll pin insertion tool and a 1/2-inch combination open-ended and box ended wrench. The punch tool is particularly important. Punches made with softer metals can expand when you try to punch out the old pin and jam in the hole, making it very difficult to remove the jammed pin. A broken hardened steel punch can destroy multiple drill bits if you have to drill out the stuck punch. Use the right tool and the correct replacement pin for best results. The roll pin insertion tool holds the pin while you tap it into place.
Removing the Old Pin
Start by aligning the two parts to each other at 90 degrees and in the same flat plane. If the parts are twisted out of alignment, the pin can be jammed. Release any securing pins or locking devices and using the correct size roll pin punch, tap the broken pin out of the hole. Don't pound the pin with a solid faced mallet to prevent expansion of the pin in the hole. If it's jammed, try soaking the areas around the pin with a rust release compound before trying again. If you can remove the entire assembly, a machinist shop may be able to press the pin out with a hydraulic press.
Prepare to insert it by collapsing one end of the roll pin. Many roll pins have a slot in one end. Slip a .010 feeler gauge into the slot and squeeze the bottom 1/8 inch of the pin over the feeler gauge. You may need to tap the end with a hammer on anvil to round the collapsed end so it's not oval.
Slip the slightly collapsed end of the roll pin into the hole. If there's a catch collar, slip it around the pin first and clip the pin in place. Protect the area around the hole and the catch collar by covering it all with masking tape before tapping the pin in place. This prevents scratching and dinging the finish, especially in exposed areas where roll pins may be used.
Securing the Pin
Turn the collapsed end of the pin upright and lay the parts on a hard surface. Use a small 1/16-inch punch to reopen the slot in the pin fully and further secure the pin in place.