Skip to content
Screws · Trade series (PEEK micro screws)

A4 (316) Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws

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

A4 Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws are supplied to ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80. Corrosion behaviour is superior, including marine and chloride environments, the material is largely non-magnetic, and the usable service range is approx. -200 °C to +400 °C, subject to the property class and the joint. In practice this grade is specified for marine, coastal and chemical applications.

Grade
ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80
Corrosion resistance
Superior, including marine and chloride environments
Magnetic response
Largely non-magnetic
Service temperature
approx. -200 °C to +400 °C, subject to the property class and the joint

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

A4 (316) Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws reference image

For peek engineering plastic micro countersunk screws in A4 Stainless Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) is summarized below together with every size supplied.

Why Choose A4 Stainless Steel for PEEK Engineering Plastic Micro Countersunk Screws

Specified for marine, coastal and chemical applications. For peek engineering plastic micro countersunk screws, this matters when superior, including marine and chloride environments is the primary requirement.

Mechanical & Physical Properties

Grade designationISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80
Magnetic responseLargely non-magnetic
Service temperatureapprox. -200 °C to +400 °C, subject to the property class and the joint
Corrosion characteristicSuperior, including marine and chloride environments

Corrosion Behavior in Service

A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For PEEK Engineering Plastic Micro Countersunk Screws in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.

Galvanic & Galling Considerations

Two important notes for stainless peek engineering plastic micro countersunk screws: (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.

Using Stainless Fasteners in Aluminum

Stainless steel is more noble than aluminum, so with an electrolyte present — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. Area ratio decides how bad it gets: a small stainless fastener in a large aluminum section is normally acceptable, a large stainless fastener in thin aluminum is not. Where the joint gets wet, isolate the metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.

Sizes of PEEK Engineering Plastic Micro Countersunk Screws Available in A4 Stainless Steel

Thread sizeExample length (mm)Head diameter (mm)DriveMaterialExample tensile break load (N)Example torsional break torque (Nu00b7m)
M1.22.52.3cross recess No. 0PEEK engineering plastic580.03
M1.42.3cross recess No. 0PEEK engineering plastic
M1.62.3cross recess No. 0PEEK engineering plastic

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Sends the selected values to the quote form below.

Request a Quote

The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.

Request a Quotation

Specification
Business Information

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

Thread sizeExample length (mm)Head diameter (mm)DriveMaterialExample tensile break load (N)Example torsional break torque (Nu00b7m)
M1.22.52.3cross recess No. 0PEEK engineering plastic580.03
M1.42.3cross recess No. 0PEEK engineering plastic
M1.62.3cross recess No. 0PEEK engineering plastic

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.

Need help matching PEEK Engineering Plastic Micro Countersunk Screws to your application? Send the assembly, the load and the environment with your enquiry and we will specify the size, material and finish against them.

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
    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
    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
    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
    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

Are A4 Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws magnetic?

A4 Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws are largely non-magnetic.

What corrosion resistance do A4 Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws offer?

A4 Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws provide superior, including marine and chloride environments with a service range of approx. -200 °C to +400 °C, subject to the property class and the joint.

Should I choose A4 Stainless Steel or A2 (304) for PEEK Engineering Plastic Micro Countersunk Screws?

For PEEK Engineering Plastic Micro Countersunk Screws, A4 Stainless Steel suits general indoor and outdoor use; A2 (304) is preferred for marine, coastal and chemical environments. Choose by corrosion exposure first.

Can A4 Stainless Steel PEEK Engineering Plastic Micro Countersunk Screws gall during installation?

Yes — stainless on stainless is prone to thread galling under load, especially at smaller sizes. Use an anti-galling lubricant or wax thread compound, and slow the tightening rate where possible.

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.