Nylon Pellet vs Standard Set Screws: Holding Power Compared
By Mutual Screw & Supply | Published: 2026-11-02
Category: Comparisons
Compare nylon pellet and standard cup point socket set screws on holding power, adjustment, and vibration resistance. Find the right 5/16-18 set screw for your application.
Quick answer
Choose nylon pellet set screws when you need vibration resistance and repeatable adjustment without damaging the shaft. Choose standard cup point socket set screws when you need maximum bite and a permanent, high-torque hold.
How the locking mechanism changes holding power
Standard cup point socket set screws rely on a concave cup tip that bites into the shaft, creating a mechanical interlock. This gives strong resistance to rotation and pull-out, but it also digs into the surface and can loosen after repeated adjustments. Nylon pellet set screws add a nylon insert that presses against the mating thread, creating friction that resists vibration. The trade-off is that the nylon pellet provides less bite than a cup point, so it may not hold as firmly under heavy shock loads.
When vibration and adjustment matter more than bite
If you frequently adjust the screw or need to protect the shaft from marring, the nylon pellet is the better choice. The nylon insert acts as a resilient brake, reducing the chance of backing out under vibration. However, because the pellet can wear or take a set over time, it may lose some holding power after many adjustments. Standard cup point screws, by contrast, maintain their bite but can damage the shaft and are harder to adjust precisely.
Trade-offs at a glance
- Holding power: Standard cup point screws offer higher resistance to rotation and pull-out because the cup tip bites into the shaft. Nylon pellet screws trade some ultimate holding power for vibration resistance. For high-torque, permanent joints, standard cup point is stronger.
- Vibration resistance: Nylon pellet screws resist backing out under vibration thanks to the nylon insert creating friction. Standard screws can loosen over time unless used with a threadlocker or locking element. In vibrating equipment, nylon pellet screws reduce maintenance.
- Shaft damage and adjustment: Cup point tips mar the shaft and are not ideal for frequent adjustment. Nylon pellet screws allow repeated adjustment with less damage, though the nylon may wear. If you adjust often or protect the shaft, choose nylon pellet.
Product facts
- 5/16-18 X 1" Nylon Pellet Cup Point Socket Set Screws | Alloy Steel (100 / Pkg.): 5/16-18 x 1" Nylon Pellet cup point socket set screws in alloy steel, sold in packs of 100. Combines a cup point for bite with a nylon pellet for vibration resistance, suitable for repeated adjustment on 5/16-18 threaded components.
5/16-18 X 1" Nylon Pellet Cup Point Socket Set Screws | Alloy Steel (100 / Pkg.)
Which set screw should you use?
Best for
- Applications with vibration where you need to prevent loosening
- Situations requiring frequent adjustment without damaging the shaft
- Use with 5/16-18 threaded components in alloy steel
Not for
- High-torque permanent joints that demand maximum bite
- Applications where the nylon pellet could be exposed to high heat or chemicals
- Use on very soft shafts where even a cup point might deform the surface
