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Seals · Trade series (PTFE thread sealing tape, colour-coded by density)

A4 (316) Stainless Steel PTFE Thread Seal Tape

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

A4 Stainless Steel PTFE Thread Seal Tape 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 PTFE Thread Seal Tape reference image

A4 Stainless Steel is not a material ptfe thread seal tape are supplied in. PTFE Thread Seal Tape are specified by inside diameter, and this combination does not describe a part that exists.

The materials that do apply are: NBR (Nitrile), FKM (Viton®-type), EPDM, Silicone (VMQ), PTFE.

See the PTFE Thread Seal Tape product page for the specifications that do apply →

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.

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Specification
Business Information

Dimensions & Specifications (Trade series (PTFE thread sealing tape, colour-coded by density))

ColourDensityIntended serviceNotes
whitestandard densitywater and general plumbinggeneral purpose
pinkhigh densitywater, larger threadsthicker, fewer wraps needed
yellowhigh densitygas linesgas-rated tape
greenoil-free, degreasedoxygen servicemust be oxygen-clean
greywith fillerstainless steel threadsreduces galling on stainless

Applications & Industries

What PTFE Thread Seal Tape are specified for, industry by industry. Stocked from white to grey (inside diameter).

Industries that specify PTFE Thread Seal Tape

  • Gas installation Gas-rated tape only.
  • Process plant Stainless thread assembly.
  • Plumbing Tapered pipe threads.
  • Compressed air Fitting and manifold joints.
  • Hydraulics & pneumatics Static and dynamic sealing in cylinders and valve bodies.
  • Process & food equipment Sealing at joints that are cleaned and inspected.

Typical applications

  • using the grey filled tape on stainless to reduce galling
  • keeping tape off the first thread so nothing enters the line
  • wrapping in the direction the fitting will turn
  • choosing the colour that matches the service
  • sealing a joint against fluid or air pressure
  • excluding dust and moisture from a housing

Service conditions to specify against

Sealed joints
Used where the fixing has to keep water or air out as well as hold — the elastomer, not the fastener, decides service life.

Where to use something else

  • Do not use general-purpose white tape on an oxygen line; oxygen service needs tape that is certified oil-free, and this is a safety requirement rather than a preference.

Full application guide: where PTFE Thread Seal Tape are used, how to specify them, and the cases they are wrong for

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

What's the service temperature limit for A4 Stainless Steel?

The practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint.

Can A4 Stainless Steel replace plated alloy steel structurally?

Only at the standard strength classes — A2-70 / A4-80 are roughly equivalent to class 7 steel; A4-100 reaches class 8.8. For class 10.9 or 12.9 strength, plated alloy steel is required.

Are A4 Stainless Steel PTFE Thread Seal Tape magnetic?

A4 Stainless Steel PTFE Thread Seal Tape are largely non-magnetic.

What corrosion resistance do A4 Stainless Steel PTFE Thread Seal Tape offer?

A4 Stainless Steel PTFE Thread Seal Tape 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.

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.