Quick answer: a push rivet has to match two things: the hole diameter and the grip range, which is the total thickness of the layers it clamps. Our 8mm push rivet has an 8mm shank (fits 8mm / 5/16" holes), a 15mm head and a 21mm overall length, and it suits a combined panel stack of roughly 2–6mm. Measure the hole and the stack, check both against the table below, and you have your answer without guessing.
Searches for a "rivet length calculator" usually come from people who have the right diameter but aren't sure whether the rivet is long enough. With push rivets you don't calculate a length from scratch. You check whether your panel stack sits inside the rivet's grip range.
The four numbers on a push rivet
| Dimension | What it means | Our 8mm rivet |
|---|---|---|
| Shank (hole) diameter | The size of hole the rivet body fits | 8mm, fits 8mm / 5/16" holes |
| Head diameter | How much panel surface the head covers | 15mm |
| Overall length | Head top to leg tip, before installation | 21mm |
| Grip range | Total thickness of the layers it can clamp | Roughly 2–6mm |
The "pin" people ask about is the centre pin in the head. You don't buy it separately; it is part of the rivet, and pressing it flush is what opens the legs.
How to measure your panel stack
- Measure at the hole. Panels are often thicker or thinner at the edge than in the middle, so measure where the rivet will go.
- Include every layer. That means the outer panel, any inner panel, trim strip or bracket, and the frame tab the rivet passes into.
- Use calipers if you have them. If you don't, stack the parts and measure with a ruler, or measure each one and add them up.
- Convert if you need to. 1 inch is 25.4mm, so 1/8" is about 3.2mm and 1/4" is about 6.4mm.
Grip range calculator
Find your measured stack in the first column.
| Panel stack | In inches | 8mm push rivet | Typical example |
|---|---|---|---|
| 1mm | 0.04" | Below the range | The legs may not open fully behind such a thin panel |
| 2mm | 0.08" (about 5/64") | In range | Single plastic panel on a frame tab |
| 3mm | 0.12" (about 1/8") | In range | Plastic panel over a metal bracket |
| 4mm | 0.16" (about 5/32") | In range | Two plastic panels overlapping |
| 5mm | 0.20" (about 3/16") | In range | Panel plus trim strip |
| 6mm | 0.24" (about 1/4") | Top of the range | Measure carefully; thicker stacks fall outside it |
| 7mm or more | 0.28"+ | Outside the range | Check the original part's length |
These figures are approximate, so a stack right at either end deserves a second measurement. If your stack is outside the range, the original fastener was probably a different length or type. Push rivets vs other clips shows how to tell them apart.
Check the hole diameter too
Length is only half the fit. Measure the hole itself, not the old rivet, because rivets deform with use. A drill bit makes a handy gauge.
| Gauge | Result | What it tells you |
|---|---|---|
| 5/16" bit slips through freely | About 8mm | 8mm push rivet |
| 5/16" bit won't go in; a 1/4" bit does | About 6mm | Smaller size; we don't stock it yet |
| A 3/8" bit slips through | About 10mm | Larger size; we don't stock it yet |
| Hole is oval or torn | Worn hole | Repair the panel; a new rivet won't fix an oval hole |
The size guide covers hole measuring in more detail and lists the OEM part numbers our 8mm rivet replaces.
Rivet spacing for new holes
When you replace rivets, use the existing holes. Their positions were set when the panel was made. If you are adding a panel or patching one and need new holes:
- Drill at 8mm (5/16") so the rivet fits the hole it was made for.
- Follow the spacing of the existing fasteners along the same edge, so the panel sits evenly.
- Keep holes back from the panel edge so the head sits fully on the panel.
- Check what is behind the panel before drilling, because the legs need room to open.
How many to order
Count the holes and add 10–15% for drops and breakage. The quantity calculator turns a job into a pack size, and how many push rivets do I need lists typical counts by job. Rivets come as singles or in 50, 100, 250, 500 and 1,000-packs. If you're working on a trailer or RV interior, the trailer and RV panel rivets are the same 8mm part. To check a vehicle, use the fitment lookup.
Orders ship via USPS within 1–2 business days from our South Carolina warehouse, and we currently ship within the United States (shipping policy).
FAQ
How do I know what size push rivet I need?
Measure the hole diameter and the total panel stack. An 8mm (5/16") hole with a stack of roughly 2–6mm matches our 8mm rivet.
Is there a push rivet length formula?
Not in the way there is for metal blind rivets. Push rivets are sold by hole size and grip range, so you measure your stack and check that it falls inside the range.
What is the length of an 8mm push rivet?
Ours is 21mm overall, with a 15mm head and an 8mm shank.
Do you sell 6mm or 10mm push rivets?
Not yet. We currently stock the 8mm size only.
Can I use a longer rivet in a thin panel?
Match the grip range rather than going longer. A stack well below the range may not let the legs open properly behind the panel.
Where do you ship?
Within the United States. Orders ship via USPS within 1–2 business days from our South Carolina warehouse.