M4 Neoprene Washers are manufactured to DIN 125 A. This page lists the controlling dimensions for the M4 size together with the installation notes for this type.
M4 Dimensional Row (DIN 125 A)
Thread size
Inner diameter d1 (mm)
Outer diameter d2 (mm)
Thickness s (mm)
Hardness (Shore A)
Temperature range (deg C)
Reference standard
M4
4.3
9
1.5
60
-35 to +100
DIN 125 A series
Common Applications for M4 Neoprene Washers
M4 Neoprene Washers are commonly specified for small electronics hardware and precision assemblies.
Mating Parts for M4
A M4 flat washer pairs with a M4 bolt/screw and matching M4 nut.
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.
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Dimensions & Specifications (DIN 125 A)
Thread size
Inner diameter d1 (mm)
Outer diameter d2 (mm)
Thickness s (mm)
Hardness (Shore A)
Temperature range (deg C)
Reference standard
M3
3.2
7
1.0
60
-35 to +100
DIN 125 A series
M4
4.3
9
1.5
60
-35 to +100
DIN 125 A series
M5
5.3
10
1.5
60
-35 to +100
DIN 125 A series
M6
6.4
12
2.0
60
-35 to +100
DIN 125 A series
M8
8.4
16
2.0
60
-35 to +100
DIN 125 A series
M10
10.5
20
3.0
60
-35 to +100
DIN 125 A series
M12
13
24
3.0
60
-35 to +100
DIN 125 A series
M16
17
30
3.0
60
-35 to +100
DIN 125 A series
Materials & Grades
Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.
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
What clearance and tapping drill suit M4?
Use a 4.5 mm clearance hole (ISO 273 medium) for through-fixing, or a 3.3 mm tapping drill for a coarse M4 thread.
Is M4 Neoprene Washers suitable for electronics and small mechanisms?
M4 Neoprene Washers is in the micro range and is widely used in electronics, instrument enclosures and small precision mechanisms. Watch the over-torque margin — micro joints strip easily.
What's the typical proof load behavior of M4 class 8.8?
Micro-thread joints are sensitive to plastic deformation in the first turn under load — use a torque-limiting driver and check the bearing surface deformation on softer mating materials.
Which washer dimensions matter most for M4?
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.
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.
Need a fastener quote or a spec sheet?Message our engineers on WhatsApp — send a drawing or DIN number and get pricing back fast.Start WhatsApp Chat →
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