---
title: "Property Class 8.8 Steel PEEK Engineering Plastic Micro Countersunk Screws"
description: "Property Class 8.8 Steel PEEK Engineering Plastic Micro Countersunk Screws (ISO 898-1 property class 8.8): requires plating (zinc) for corrosion protection."
url: https://engineeringhardware.com/guide/material/grade-8-8-steel-peek-engineering-plastic-micro-countersunk-screws/
source: Engineering Hardware & Fasteners
---

# Property Class 8.8 Steel PEEK Engineering Plastic Micro Countersunk Screws

Screws · Trade series (PEEK micro screws)

Mechanical properties, corrosion behaviour and the full dimensional range for this grade.

Property Class 8.8 Steel PEEK Engineering Plastic Micro Countersunk Screws are supplied to ISO 898-1 property class 8.8. Corrosion behaviour is requires plating (zinc) for corrosion protection, the material is magnetic, and the usable service range is commonly limited to approx. +300 °C; confirm against the coating and the load. In practice this grade is the workhorse medium-carbon alloy class for structural joints.

- **Grade:** ISO 898-1 property class 8.8
- **Corrosion resistance:** Requires plating (zinc) for corrosion protection
- **Magnetic response:** Magnetic
- **Service temperature:** commonly limited to approx. +300 °C; confirm against the coating and the load

Property values are typical for the grade. Certified mechanical test data is available on request for production orders.

![Property Class 8.8 Steel PEEK Engineering Plastic Micro Countersunk Screws reference image](https://engineeringhardware.com/wp-content/uploads/2026/09/PEEK-RENY-Plastic-Micro-Countersunk-Screws.webp)

Material page for peek engineering plastic micro countersunk screws in Property Class 8.8 Steel (ISO 898-1 property class 8.8). The sizes below are the ones we supply; there is no published dimensional standard for this article, so the table rather than a standard number is what to quote. Corrosion behaviour is requires plating (zinc) for corrosion protection and the service range is commonly limited to approx. +300 °C; confirm against the coating and the load.

## Why Choose Property Class 8.8 Steel for PEEK Engineering Plastic Micro Countersunk Screws

The workhorse medium-carbon alloy class for structural joints. For peek engineering plastic micro countersunk screws, this matters when requires plating (zinc) for corrosion protection is the primary requirement.

## Mechanical & Physical Properties

| Grade designation | ISO 898-1 property class 8.8 |
| --- | --- |
| Magnetic response | Magnetic |
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
| Corrosion characteristic | Requires plating (zinc) for corrosion protection |

## Corrosion Behavior in Service

Carbon and alloy steel peek engineering plastic micro countersunk screws require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.

## Comparable Grades

For PEEK Engineering Plastic Micro Countersunk Screws, class 10.9 or 12.9 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.

## Sizes of PEEK Engineering Plastic Micro Countersunk Screws Available in Property Class 8.8 Steel

| Thread size | Example length (mm) | Head diameter (mm) | Drive | Example tensile break load (N) | Example torsional break torque (Nu00b7m) |
| --- | --- | --- | --- | --- | --- |
| M1.2 | 2.5 | 2.3 | cross recess No. 0 | 58 | 0.03 |
| M1.4 |  | 2.3 | cross recess No. 0 |  |  |
| M1.6 |  | 2.3 | cross recess No. 0 |  |  |

Dimensions are independent of the material: the table above lists the sizes supplied, and on this page every one of them is quoted in Property Class 8.8 Steel. The catalogue's default material column has been omitted here so it cannot be read as contradicting that.

Custom manufacturing · Made to drawing

## Need this screw in a grade that is not listed?

Grade 8 8 Steel is one of the grades the catalog describes. Lengths and thread lengths outside the standard table are the commonest request, followed by a drive the standard does not offer and a head marked with your own part number. Made by cold heading or warm forging.

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

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

## Technical Drawing

Dimensioned line drawing of M1.2 PEEK Engineering Plastic Micro Countersunk Screws to Trade series (PEEK micro screws). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Example length (mm):** 2.5
- **Head diameter (mm):** 2.3
- **Drive:** cross recess No. 0
- **Material:** PEEK engineering plastic
- **Example tensile break load (N):** 58
- **Example torsional break torque (Nu00b7m):** 0.03

## Dimensions & Specifications (Trade series (PEEK micro screws))

| Thread size | Example length (mm) | Head diameter (mm) | Drive | Material | Example tensile break load (N) | Example torsional break torque (Nu00b7m) |
| --- | --- | --- | --- | --- | --- | --- |
| M1.2 | 2.5 | 2.3 | cross recess No. 0 | PEEK engineering plastic | 58 | 0.03 |
| M1.4 |  | 2.3 | cross recess No. 0 | PEEK engineering plastic |  |  |
| M1.6 |  | 2.3 | cross recess No. 0 | PEEK engineering plastic |  |  |

Product catalog

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## Applications & Industries

PEEK Engineering Plastic Micro Countersunk Screws are bought for a small number of well-defined jobs. These are the ones we ship them for. Stocked from M1.2 to M1.6.

### Industries that specify PEEK Engineering Plastic Micro Countersunk Screws

- **Prototype assemblies:** Countersunk plastic screws avoid a metal head near the component.
- **Insulated electronics:** Engineering-plastic screws provide a nonconductive threaded joint in a compact package.
- **Vacuum and analytical equipment:** Low-outgassing plastic is used around sensitive instruments.
- **Chemical equipment:** PEEK resists service environments where ordinary metal hardware may be unsuitable.
- **Automotive & transport:** Chassis, driveline and body fixings that see vibration and are assembled to a controlled preload.
- **Steel fabrication:** Bolted connections in frames, enclosures, walkways and weldments, on the bench and on site.

### Typical applications

- using the 90-degree head seat and No. 0 recess
- providing electrical insulation with a miniature countersunk screw
- checking the documented break loads instead of borrowing metal-screw torque
- matching the plastic screw to the parent thread without over-driving it
- joints where the property class is stated on the drawing
- clamping two machined faces to a calculated preload

### Service conditions to specify against

- **Marine and coastal:** Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
- **High load:** Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
- **Torque and preload:** The joint is designed around bolt tension, so lubrication, coating and the friction coefficient all change the torque figure — state them together.

### Where to use something else

- Do not substitute metal-fastener torque for the plastic break-torque example; over-driving can fracture the screw.
- Do not use a machine thread into unthreaded sheet or timber; use a tapping screw, rivet nut or insert made for that parent material.

[Full application guide: where PEEK Engineering Plastic Micro Countersunk Screws are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/peek-engineering-plastic-micro-countersunk-screws/)

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

### Is Property Class 8.8 Steel prone to hydrogen embrittlement?

Class 10.9 and above can be susceptible to hydrogen embrittlement when electroplated. Specify post-plating baking, or use mechanical-zinc / zinc-flake finishes which avoid the cathodic plating step.

### Which finish is best for outdoor PEEK Engineering Plastic Micro Countersunk Screws?

For outdoor service in steel, hot-dip galvanizing gives the longest life; zinc-flake (Geomet/Delta-Tone family) gives a thinner film with excellent salt-spray performance; standard zinc plating is the lowest-cost option for general indoor / shielded outdoor use.

### What's the service temperature limit for Property Class 8.8 Steel?

The practical service range is commonly limited to approx. +300 °C; confirm against the coating and the load.

### Can Property Class 8.8 Steel replace stainless steel structurally?

No — stainless A2/A4 cannot match class 10.9 / 12.9 strength. Stainless is selected for corrosion, not raw strength.

### How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.

## Related Pages

[View the full PEEK Engineering Plastic Micro Countersunk Screws page](https://engineeringhardware.com/fastener/peek-engineering-plastic-micro-countersunk-screws/)

### More PEEK Engineering Plastic Micro Countersunk Screws Guides