---
title: "What Are Push-On Nuts (Starlock Retainers) Used For?"
description: "Push-On Nuts (Starlock Retainers) (Trade series (push-on retaining washer)) are used for retaining a component on a plain unthreaded shaft, permanently and w…"
url: https://engineeringhardware.com/applications/push-on-nuts/
source: Engineering Hardware & Fasteners
---

# What Are Push-On Nuts (Starlock Retainers) Used For?

Nuts · Trade series (push-on retaining washer) · Application guide

Typical applications, the industries that specify push-on nuts (starlock retainers), and how to choose the right size, material and finish for the joint.

Push-On Nuts (Starlock Retainers) are used for retaining a component on a plain unthreaded shaft, permanently and without machining a groove. They are manufactured to Trade series (push-on retaining washer), and selection is driven by the shaft / bore diameter, the fit and tolerance the assembly requires, and the service environment.

- **Primary duty:** Retaining a component on a plain unthreaded shaft, permanently and without machining a groove
- **Governing standard:** Trade series (push-on retaining washer)
- **Shaft / bore diameter range:** 3 mm to 10 mm
- **Category:** Nuts

Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation.

![What Are Push-On Nuts (Starlock Retainers) Used For? application image](https://engineeringhardware.com/wp-content/uploads/2026/08/Push-Nuts.webp)

Application guide for Push-On Nuts (Starlock Retainers) to Trade series (push-on retaining washer). The core duty of the type is retaining a component on a plain unthreaded shaft, permanently and without machining a groove. The typical industries, the how-to-specify checklist, assembly practice and the exclusion cases are set out below. Stocked across roughly 3 mm to 10 mm, they cover general to heavy-duty work.

## Typical Applications for Push-On Nuts (Starlock Retainers)

The most common settings where these are specified:

- **Fabrication & metalwork:** bench and on-site assembly of steel frames, enclosures and weldments.
- **Bolted joints:** the clamping counter-face on studs and bolts across every assembly type.
- **Vibration-prone equipment:** where a locking or flanged style resists loosening.
- **Frames & weldments:** captive or welded options for repeatable assembly.
- **General machine building:** fastening covers, brackets, motors and sub-assemblies on production equipment.

Product catalog

## Related Push-On Nuts & Retainers products

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Cage, Clip, Speed & Push Nuts

### [China Supplier Wholesale Milti Clip U Spring Clips Fasteners Speed Nut](https://engineeringhardware.com/product/china-supplier-wholesale-milti-clip-u-spring-clips-fasteners-speed-nut/)

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**US$0.0012 – 0.048**MOQ 10,000 pieces

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### [#10-32 #12-24 5/16-24 1/4-20 5/16-18 3/8-16 7/16 Inch Cage Nuts](https://engineeringhardware.com/product/10-32-12-24-5-16-24-1-4-20-5-16-18-3-8-16-7-16-inch-cage-nuts/)

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**US$0.048 – 6.00**MOQ 100 pieces

[View all Cage, Clip, Speed & Push Nuts →](https://engineeringhardware.com/fastener-products/nuts/cage-clip-speed-push-nuts/) [Full product catalog](https://engineeringhardware.com/products/)

## How to Specify Push-On Nuts (Starlock Retainers) for Your Application

- **Size:** Select on nominal diameter, then on the hole tolerance and fit class — the fit, not the diameter alone, determines whether the part locates or slips. This product spans 3 mm–10 mm; check the full table below for the exact dimensions of each size.
- **Locking & grade:** Match the strength grade to the bolt, and choose a locking style (nyloc, all-metal, serrated flange) if the joint sees vibration.
- **Environment:** For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- **Standard:** This product is supplied to Trade series (push-on retaining washer). Quoting the standard on your order guarantees interchangeable dimensions between suppliers.

## Installation & Assembly Practice

- Run the nut down by hand before applying the wrench to catch cross-threading early.
- Tighten the nut rather than the bolt head where access allows — the torque-to-preload relation is more consistent.
- For locking styles, note that nyloc inserts are single-use in critical joints and lose grip above roughly 120 °C.

## Common Selection Mistakes with Push-On Nuts (Starlock Retainers)

- Pairing a high-class bolt with a lower-class nut — the nut strips before the bolt reaches proof load; the nut class must meet or exceed the bolt class.
- Using a plain nut with a spring washer in severe vibration instead of a prevailing-torque locking nut.
- Re-using nyloc nuts in critical joints.

## Where Push-On Nuts (Starlock Retainers) Are Not the Right Choice

Not on their own — they need a matching bolt or stud — and a plain nut is not a substitute for a locking type under heavy vibration.

Custom manufacturing · Made to drawing

## Need a push-on nuts (starlock retainers) outside the standard range?

Temper and thickness set the thrust the ring will take, and both are specifiable against the load rather than picked from a table. Made by cold heading or tapping.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

[Custom nut manufacturing](https://engineeringhardware.com/custom/nuts/)[Send a drawing](https://engineeringhardware.com/custom/nuts/#rfq)

## Technical Drawing

Dimensioned line drawing of 3.0 Push-On Nuts (Starlock Retainers) to Trade series (push-on retaining washer). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Outer diameter (mm):** 11.0
- **Thickness (mm):** 0.25
- **Teeth:** 12
- **Push-off resistance (N, typical):** 150
- **Material:** Spring steel
- **Finish:** Bright zinc
- **Reusable:** No

## Dimensions & Specifications (Trade series (push-on retaining washer))

| For shaft diameter (mm) | Outer diameter (mm) | Thickness (mm) | Teeth | Push-off resistance (N, typical) | Material | Finish | Reusable |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 3.0 | 11.0 | 0.25 | 12 | 150 | Spring steel | Bright zinc | No |
| 4.0 | 12.0 | 0.25 | 12 | 220 | Spring steel | Bright zinc | No |
| 5.0 | 15.0 | 0.30 | 12 | 320 | Spring steel | Bright zinc | No |
| 6.0 | 18.0 | 0.30 | 12 | 420 | Spring steel | Bright zinc | No |
| 8.0 | 21.0 | 0.40 | 12 | 600 | Spring steel | Bright zinc | No |
| 10.0 | 26.0 | 0.40 | 12 | 780 | Spring steel | Bright zinc | No |

Inside the plant

## Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

1. ![Wire rod feeding into a cold heading machine](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 01 **Cold heading** Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail. Head dimensions and under-head radius checked at set-up and per shift.
2. ![Thread rolling machine producing bolt threads](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 02 **Thread rolling** Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch. Go / no-go ring gauges to ISO 965 tolerance class 6g.
3. ![Baskets of bolts staged for heat treatment](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 03 **Heat treatment** Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it. Core hardness and tensile tested per lot to ISO 898-1.
4. ![Zinc plated bolts in a treatment basket](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 04 **Surface treatment** Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list. Coating thickness and neutral salt spray hours to ISO 9227.

## Frequently Asked Questions

### How do I choose the right size of Push-On Nuts (Starlock Retainers)?

Select on shaft / bore diameter and on the fit the assembly requires. This product is available from 3 mm to 10 mm; the full dimension table on this page lists each size.

### Do Push-On Nuts (Starlock Retainers) need a locking feature?

If the joint sees vibration or cyclic load, use a locking style (nyloc, all-metal lock, or serrated flange) or a thread-locking adhesive. For static joints a standard nut tightened correctly is usually sufficient.

### What material should Push-On Nuts (Starlock Retainers) be for outdoor use?

For damp, coastal or chemical environments specify A4 (316) stainless or a suitably coated steel. For indoor or dry use, A2 (304) stainless or zinc-plated steel is normally adequate.

### Are Push-On Nuts (Starlock Retainers) made to a recognized standard?

Yes — they are manufactured to Trade series (push-on retaining washer), so dimensions are interchangeable between suppliers when you quote the standard on your order.

### Can I get a quote for Push-On Nuts (Starlock Retainers) in the size and material I need?

Yes. Use the technical drawing and quote form on this page to set the size and options, then send the exact configuration to our team for pricing and lead time.

## Related Pages

Product page: [Push-On Nuts (Starlock Retainers) — specifications & sizes](https://engineeringhardware.com/fastener/push-on-nuts/)

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