Plastic welding staples: wave, M, L or corner, 0.6 or 0.8 mm — how to choose for your repair
Wave staples are for straight cracks, M- and L-shaped and corner staples are for corners and ribs, 0.6 mm is for thin plastic, 0.8 mm is for bumpers. A selection table, packs of 100/300/500 pcs and tips to make the staple hold.
Choose the staple shape based on where the crack is: wave staples (small or large wave) — for straight cracks on flat areas; M-shaped, L-shaped and corner staples — for corners, ribs and mounts; S-shaped — for long cracks and curved panels. Choose the thickness based on the thickness of the plastic: 0.6 mm — for thin-walled parts (interior panels, appliance housings, motorcycle plastics), 0.8 mm — for bumpers and load-bearing parts. Stainless steel staples are melted into the plastic with a hot stapler; at Yellow Square the main types cost 42 ₴ per 100 pcs.
A plastic welding staple is a piece of steel wire bent into a specific shape. A hot stapler heats it in a few seconds, the staple melts into the plastic across the crack and, once it cools, holds the edges together like reinforcement. Whether the repair survives vibration and impacts depends on choosing the right shape and thickness.
Staple selection table
| Shape | Where it is used | Thicknesses we stock |
|---|---|---|
| Small wave | straight cracks on flat areas, neat seams | 0.6 mm, 0.8 mm |
| Large (high) wave | wider cracks and thicker plastic — the wave grips the edges more deeply | 0.6 mm, 0.8 mm |
| M-shaped (corner) | seams in the corners of bumpers, mounts and housings | 0.6 mm |
| L-shaped (corner) | corner seams and mounts | 0.8 mm |
| Corner staples for outside corners | ribs and outside corners of a bumper, brackets | 0.8 mm |
| For inside seams | repairs from the inside, inside corners, cavities | 0.8 mm |
| Flat corner staples | bumper corners, interior panels, hard-to-reach places | 0.6 mm |
| S-shaped | long cracks, brackets, curved panels | 0.6 mm |
0.6 or 0.8 mm — which thickness to choose
- 0.6 mm — thin wire: it melts in more easily and sticks out less from thin plastic. For interior panels, decorative trim, household appliance housings, motorcycles and ATVs.
- 0.8 mm — a stronger staple for bumpers, body kits and parts that work under load and vibration.
The rule is simple: the staple must not go all the way through the plastic. If the part is thin, choose 0.6 mm so the ends do not poke out on the front side.
How many staples you need
Staples are placed across the crack roughly every 1–1.5 cm, so a 10 cm crack takes 8–10 staples. A pack of 100 is enough for one or two repairs; for car repair shops, packs of 300 and 500 are better value. The main types — small and large wave in 0.6 and 0.8 mm, M- and L-shaped — cost 42 ₴ per 100 pcs.
What to melt the staples in with
Staples are melted in with a hot stapler (also called a thermal stapler) — it heats the staple with electric current in a few seconds and holds it while you press it into the plastic. For the hot stapler for bumpers with 200 staples and other Yellow Square hot staplers, these staples are sold as consumables — the manufacturer lists them among the compatible staples. For a step-by-step bumper repair guide, see the article “How to repair a cracked bumper with a hot stapler”.
Questions and answers
Which staples should I use for a bumper?
For straight cracks — 0.8 mm wave staples (small or large wave); for corners and mounts — M-shaped, L-shaped or corner staples. If the plastic is thin, choose 0.6 mm.
What is the difference between a small wave and a large wave?
A large (high) wave grips the edges of the crack more deeply — it is used for wider cracks and thicker plastic. A small wave gives a neater seam on flat areas.
Which plastics are the staples suitable for?
For the thermoplastics that bumpers and housings are made of — ABS, PP, PE — and also for rubber. These staples are not intended for metal, wood or glass.
Can I install staples without a hot stapler?
No: the staple has to be heated to melt into the plastic. For this you need a hot stapler or a plastic welding iron with staples.
Where to buy hot stapler staples in Ukraine?
At Yellow Square: small and large wave, M- and L-shaped, corner and S-shaped staples in 0.6 and 0.8 mm, in packs of 100, 300 and 500 pcs — from 42 ₴ per 100 pcs, with delivery across Ukraine.
