M6 EPDM Sealing Washers (Industry standard): the row from the product table, what the nominal bolt size controls in the assembly, and the notes that matter when specifying this size.
M6 Dimensional Row (Industry standard)
Screw size
Inner diameter d1 (mm)
Outer diameter d2 (mm)
Total thickness s (mm)
EPDM thickness (mm)
Backing material
Temperature range (deg C)
Reference standard
M6
6.4
19
2.5
1.5
A2 stainless
-40 to +130
Industry standard
Mating Parts for M6
A M6 flat washer pairs with a M6 bolt/screw and matching M6 nut.
Custom manufacturing · Made to drawing
Need EPDM sealing washers in a size this table does not list?
This page covers M6 EPDM sealing washers. Bore, outside diameter, thickness, temper and finish are the variables here — there is no thread to specify, so the fit and the bearing area are what the drawing has to pin down. Made by stamping or punching.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
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.
Dimensioned line drawing of M6 EPDM Sealing Washers to Industry standard. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Inner diameter d1 (mm)
6.4
Outer diameter d2 (mm)
19
Total thickness s (mm)
2.5
EPDM thickness (mm)
1.5
Backing material
A2 stainless
Temperature range (deg C)
-40 to +130
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.
Dimensions & Specifications (Industry standard)
Screw size
Inner diameter d1 (mm)
Outer diameter d2 (mm)
Total thickness s (mm)
EPDM thickness (mm)
Backing material
Temperature range (deg C)
Reference standard
No.8 (4.2 mm)
4.3
11
2.0
1.0
Galvanised steel
-40 to +130
Industry standard
No.10 (4.8 mm)
5.0
14
2.0
1.0
Galvanised steel
-40 to +130
Industry standard
No.12 (5.5 mm)
5.6
16
2.5
1.5
Galvanised steel
-40 to +130
Industry standard
No.14 (6.3 mm)
6.4
19
2.5
1.5
Galvanised steel
-40 to +130
Industry standard
M6
6.4
19
2.5
1.5
A2 stainless
-40 to +130
Industry standard
M8
8.4
22
3.0
2.0
A2 stainless
-40 to +130
Industry standard
M10
10.5
25
3.0
2.0
A2 stainless
-40 to +130
Industry standard
Applications & Industries for M6 EPDM Sealing Washers
EPDM Sealing Washers are bought for a small number of well-defined jobs. These are the ones we ship them for. Stocked from No.8 (4.2 mm) to M10 (nominal bolt size).
Industries that specify EPDM Sealing Washers
Roofing & claddingFixings that must keep water out.
Automotive serviceService items replaced at every oil change.
Hydraulics & fuel systemsBanjo bolts, sump plugs and pressure fittings.
Rotating & vibrating plantSpring, tooth and wedge types that maintain or lock bolt tension.
Steel fabricationSpreading load under a head or nut and protecting the surface finish.
Machine building & OEMSetting bearing area on soft alloy, plastic and oversized holes.
Typical applications
crush washers are single use by design
sealing a threaded fitting against pressure
protecting a painted or plated surface under a turned nut
maintaining bolt tension in a joint that settles
spreading clamp load over a soft or oversized bearing face
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.
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.
Exterior structural
Hot-dip galvanised options for external steelwork; allow for the thicker coating in the mating thread.
Hardness matters
Under a high-strength bolt a soft washer embeds into the joint and preload is lost — specify a hardened washer for structural bolting.
Third-party video, selected automatically for this topic. It is not produced by Engineering Hardware and is not a specification source — use the tables on this page for dimensional data.
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.
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.
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.
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.
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
Which washer dimensions matter most for M6?
For a flat washer, the outside diameter (the bearing surface) and the thickness control how the load is spread under the head and how much elastic preload is preserved. The inside diameter must clear the bolt body but not be so large that the head bears mostly on the washer's outer rim.
What is the coarse-thread pitch of M6 for EPDM Sealing Washers?
For M6 the standard coarse pitch is 1 mm — this is the value used for EPDM Sealing Washers.
What clearance and tapping drill suit M6?
Use a 6.6 mm clearance hole (ISO 273 medium) for through-fixing, or a 5 mm tapping drill for a coarse M6 thread.
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.
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