---
title: "M16 Aluminum Flat Sealing Washers Dimensions"
description: "M16 Aluminum Flat Sealing Washers: inside diameter 16.2 mm, outside diameter 19.9 mm, thickness 1 mm. Full size chart to DIN 7603 Type A with tolerances."
url: https://engineeringhardware.com/guide/size/m16-aluminum-flat-sealing-washers-din-7603/
source: Engineering Hardware & Fasteners
---

# M16 Aluminum Flat Sealing Washers Dimensions

Washers · DIN 7603 Type A

Controlling dimensions to DIN 7603 Type A, with tolerances and fit.

M16 Aluminum Flat Sealing Washers dimensions to DIN 7603 Type A: inside diameter 16.2 mm, outside diameter 19.9 mm, thickness 1 mm.

- **Inside diameter:** 16.2 mm
- **Outside diameter:** 19.9 mm
- **Thickness:** 1 mm

Figures are nominal values from the governing standard. Confirm against the tolerance class for your application before machining or ordering.

![M16 Aluminum Flat Sealing Washers Dimensions reference image](https://engineeringhardware.com/wp-content/uploads/2026/09/Aluminium-Flat-Sealing-Washers.webp)

M16 Aluminum Flat Sealing Washers (DIN 7603 Type A): the row from the product table, what the nominal bolt size controls in the assembly, and the notes that matter when specifying this size.

## M16 Dimensional Row (DIN 7603 Type A)

| For bolt size | Pitch (mm) | Inside diameter (mm) | Outside diameter (mm) | Thickness options (mm) | Material | Reference standard |
| --- | --- | --- | --- | --- | --- | --- |
| M16 | 1.5 | 16.2 | 19.9 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |

## Mating Parts for M16

A M16 flat washer pairs with a M16 bolt/screw and matching M16 nut.

Custom manufacturing · Made to drawing

## Need aluminum flat sealing washers in a size this table does not list?

This page covers M16 aluminum flat 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.

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

## Technical Drawing

Dimensioned line drawing of M16 Aluminum Flat Sealing Washers to DIN 7603 Type A. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Pitch (mm):** 1.5
- **Inside diameter (mm):** 16.2
- **Outside diameter (mm):** 19.9
- **Thickness options (mm):** 1.0 / 1.5 / 2.0
- **Material:** aluminum

## Dimensions & Specifications (DIN 7603 Type A)

| For bolt size | Pitch (mm) | Inside diameter (mm) | Outside diameter (mm) | Thickness options (mm) | Material | Reference standard |
| --- | --- | --- | --- | --- | --- | --- |
| M8 | 1.0 | 8.2 | 11.4 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |
| M10 | 1.0 | 10.2 | 13.4 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |
| M12 | 1.5 | 12.2 | 15.9 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |
| M14 | 1.5 | 14.2 | 17.9 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |
| M16 | 1.5 | 16.2 | 19.9 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |
| M20 | 1.5 | 20.2 | 23.9 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |
| M30 | 1.5 | 30.3 | 35.9 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |
| M48 | 2.0 | 48.3 | 54.9 | 1.0 / 1.5 / 2.0 | aluminum | DIN 7603 Type A |

Product catalog

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Bonded, Sealing & Roofing Washers

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## 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.

Stainless Steel38 Carbon Steel66 Alloy Steel41 Bearing Steel5 Spring Steel25 Aluminum and Aluminum Alloys21 Brass17 Bronze11 Copper8 Titanium and Titanium Alloys18 Nickel and Nickel Alloys22 Iron-Nickel and High-Temperature Alloys10 Tool Steel and Specialty Hardened Steel9 Structural and Construction Steel9

### Stainless Steel

#### Austenitic Stainless Steel

- A1 AISI 303 · SAE 303 · SUS303 · EN 1.4305 · X8CrNiS18-9
- A2 AISI 304 · SAE 304 · SUS304 · EN 1.4301 · X5CrNi18-10 · 06Cr19Ni10
- 304L AISI 304L · SUS304L · EN 1.4307 · X2CrNi18-9 · 022Cr19Ni10
- 302 AISI 302 · SUS302 · EN 1.4310
- 305 AISI 305 · SUS305 · EN 1.4303
- A4 AISI 316 · SAE 316 · SUS316 · EN 1.4401 · X5CrNiMo17-12-2 · 06Cr17Ni12Mo2
- 316L AISI 316L · SUS316L · EN 1.4404 · X2CrNiMo17-12-2 · 022Cr17Ni12Mo2
- 321 AISI 321 · SUS321 · EN 1.4541 · X6CrNiTi18-10
- 310 / 310S AISI 310 · AISI 310S · SUS310S · EN 1.4845
- 302HQ AISI 302HQ
- A3
- A5
- 347 AISI 347 · SUS347 · EN 1.4550 · X6CrNiNb18-10
- 309 / 309S AISI 309 · AISI 309S · SUS309S

#### Martensitic Stainless Steel

- AISI 410 SUS410 · EN 1.4006 · X12Cr13 · 12Cr13
- AISI 420 SUS420J1 · SUS420J2 · EN 1.4021 · EN 1.4028 · 20Cr13 · 30Cr13
- AISI 431 SUS431 · EN 1.4057 · X17CrNi16-2
- C1
- C3
- C4
- AISI 440A
- AISI 440B
- AISI 440C SUS440C · EN 1.4125

#### Ferritic Stainless Steel

- AISI 430 SUS430 · EN 1.4016 · X6Cr17 · 10Cr17
- F1
- AISI 434
- AISI 444

#### Precipitation-Hardening Stainless Steel

- 17-4 PH AISI 630 · UNS S17400 · SUS630 · EN 1.4542 · X5CrNiCuNb16-4
- 15-5 PH UNS S15500
- 17-7 PH UNS S17700

#### Duplex and Super Duplex Stainless Steel

- Duplex 2205 UNS S31803 · UNS S32205 · EN 1.4462
- Super Duplex 2507 UNS S32750 · EN 1.4410
- D2
- D4
- D6
- D8
- Lean Duplex 2101 UNS S32101
- Super Duplex S32760 UNS S32760 · EN 1.4501

### Carbon Steel

#### Low-Carbon Steel

- SAE 1006
- SAE 1008
- SAE 1010
- SAE 1018
- SAE 1020
- Q195
- Q235
- SAE 1012
- SAE 1015
- Q215
- ML08
- ML08Al
- ML10
- ML15
- ML20
- SWRCH6A
- SWRCH8A
- SWRCH10A
- SWRCH12A
- SWRCH15A
- SWRCH18A

#### Medium-Carbon Steel

- SAE 1035
- SAE 1045
- S45C
- C45
- SAE 1030
- SAE 1040
- SAE 1050
- 30
- 35
- 40
- 45
- 50
- S35C
- S40C
- S50C
- C35
- C40

#### High-Carbon Steel

- SAE 1060
- SAE 1070
- 65Mn
- SAE 1065
- SAE 1075
- SAE 1080
- SAE 1085
- SAE 1090
- SAE 1095
- 60
- 65
- 70
- 75
- 80
- 85

#### Cold-Heading Steel

- SWRCH22A
- 10B21
- SWRCH22K
- SWRCH25K
- SWRCH30K
- SWRCH35K
- SWRCH40K
- ML20Mn
- ML25
- ML30
- ML35
- ML40
- 15B25

### Alloy Steel

#### Chromium Steel

- 40Cr
- 45Cr
- AISI 5140
- SAE 5140
- AISI 5120
- SAE 5120
- SCr420
- SCr440

#### Chromium-Molybdenum Steel

- 35CrMo
- 42CrMo
- AISI 4140
- SCM435
- SCM440
- 42CrMo4
- 30CrMo
- AISI 4130
- SAE 4130
- SAE 4140
- AISI 4142
- AISI 4145
- SCM415
- SCM420
- SCM445
- EN 1.7220
- EN 1.7225
- 25CrMo4
- 34CrMo4

#### Nickel-Chromium-Molybdenum Steel

- AISI 4340
- SAE 4340
- 40CrNiMo
- SNCM439
- EN 1.6511
- 36CrNiMo4

#### Boron Alloy Steel

- 10B22
- 10B21
- 15B21
- 15B25
- 20MnTiB
- 20Mn2B
- 35VB
- 40MnB

### Bearing Steel

#### Bearing Steel

- GCr15
- AISI 52100 SAE 52100 · UNS G52986
- SUJ2
- 100Cr6 EN 1.3505
- GCr15SiMn

### Spring Steel

#### Carbon Spring Steel

- SAE 1065
- SAE 1070
- SAE 1075
- SAE 1080
- SAE 1095
- 65
- 70
- 75
- 80
- 65Mn

#### Silicon-Manganese Spring Steel

- 60Si2Mn
- 60Si2MnA
- SUP6
- SUP7

#### Chromium-Vanadium Spring Steel

- 50CrVA
- SAE 6150
- AISI 6150
- SUP10

#### Stainless Spring Steel

- AISI 301
- SUS301
- EN 1.4310
- AISI 302
- AISI 304
- AISI 316
- 17-7 PH

### Aluminum and Aluminum Alloys

#### Commercially Pure Aluminum

- 1050
- 1060
- 1070
- 1100

#### 2xxx Series Aluminum

- 2024
- 2011
- 2014
- 2017

#### 5xxx Series Aluminum

- 5052
- 5083
- 5754

#### 6xxx Series Aluminum

- 6061
- 6061-T6
- 6063
- 6082
- 6082-T6

#### 7xxx Series Aluminum

- 7075
- 7075-T6
- 7005
- 7050
- 7075-T73

### Brass

#### Free-Cutting Brass

- C36000
- H62
- HPb59-1
- C3601
- C3602
- C3604
- CuZn36Pb3
- CuZn39Pb3
- EN CW614N
- EN CW617N
- H65

#### Lead-Free Brass

- C69300
- C27450
- CW510L
- CW511L

#### Naval Brass

- C46400
- CuZn39Sn1

### Bronze

#### Silicon Bronze

- C65500
- C65100
- C65600

#### Phosphor Bronze

- C51000
- C52100
- CuSn6
- CuSn8

#### Aluminum Bronze

- C95400
- C95500
- C63000
- CuAl10Ni5Fe4

### Copper

#### Copper

- C11000
- T2
- C10100
- C10200
- C12200
- T1
- TU1
- TU2

### Titanium and Titanium Alloys

#### Commercially Pure Titanium

- Grade 2
- Grade 1
- Grade 3
- Grade 4
- TA1
- TA2
- TA3

#### Alpha-Beta Titanium Alloys

- Grade 5
- Ti-6Al-4V
- TC4
- UNS R56400

#### Low-Interstitial Grade

- Grade 23
- Ti-6Al-4V ELI
- UNS R56407

#### Other Titanium Fastener Alloys

- Ti-6Al-6V-2Sn
- Ti-6Al-2Sn-4Zr-2Mo
- Beta-C titanium
- Ti-10V-2Fe-3Al

### Nickel and Nickel Alloys

#### Commercially Pure Nickel

- Nickel 200
- UNS N02200
- Nickel 201
- UNS N02201

#### Inconel Alloys

- Inconel 625 UNS N06625
- Inconel 718 UNS N07718
- Inconel 600 UNS N06600
- Inconel 601 UNS N06601
- Inconel 686 UNS N06686
- Inconel X-750 UNS N07750

#### Monel Alloys

- Monel 400 UNS N04400
- Monel K-500 UNS N05500

#### Hastelloy Alloys

- Hastelloy C-276 UNS N10276
- Hastelloy C-22 UNS N06022
- Hastelloy B-2 UNS N10665
- Hastelloy B-3 UNS N10675
- Hastelloy X UNS N06002

#### Other Nickel Alloys

- Alloy 20 UNS N08020
- Alloy 625
- Alloy 718
- Alloy 825 UNS N08825
- Alloy 925 UNS N09925

### Iron-Nickel and High-Temperature Alloys

#### A286

- A-286
- UNS S66286
- EN 1.4980

#### Invar

- Invar 36
- Alloy 36
- UNS K93600
- FeNi36

#### Alloy 42

- Alloy 42
- UNS K94100
- FeNi42

### Tool Steel and Specialty Hardened Steel

#### Tool Steel and Specialty Hardened Steel

- AISI D2
- AISI H13
- SKD11
- Cr12MoV
- AISI O1
- AISI A2
- AISI S7
- SKD61
- 9CrSi

### Structural and Construction Steel

#### Structural and Construction Steel

- ASTM A36
- Q235B
- Q355B
- S355JR
- Q235C
- Q355C
- S235JR
- S275JR
- S355J2

## Applications & Industries for M16 Aluminum Flat Sealing Washers

Where Aluminum Flat Sealing Washers are used, and what decides the specification in each case. Stocked from M8 to M48 (nominal bolt size).

### Industries that specify Aluminum Flat Sealing Washers

- **Hydraulic service:** Crush seals under banjo bolts, plugs and threaded fittings.
- **Fuel systems:** Soft-metal sealing at machined fitting faces.
- **Automotive maintenance:** Single-use sealing washers replaced during fluid service.
- **Pneumatic equipment:** Lightweight sealing at air and instrument connections.
- **Steel fabrication:** Spreading load under a head or nut and protecting the surface finish.
- **Machine building & OEM:** Setting bearing area on soft alloy, plastic and oversized holes.

### Typical applications

- crushing a flat aluminum ring between two machined faces
- sealing a threaded fitting without an elastomer gasket
- matching the inside and outside diameters to the fitting seat
- replacing the washer after it has been compressed in service
- 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.
- **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.

### Where to use something else

- Do not reuse a crushed washer or tighten it against a damaged sealing face; leakage is the usual result.

[Full application guide: where Aluminum Flat Sealing Washers are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/aluminum-flat-sealing-washers-din-7603/)

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

### Which washer dimensions matter most for M16?

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 M16 for Aluminum Flat Sealing Washers?

For M16 the standard coarse pitch is 1.5 mm — this is the value used for Aluminum Flat Sealing Washers.

### What clearance and tapping drill suit M16?

Use a 17.5 mm clearance hole (ISO 273 medium) for through-fixing, or a 14.5 mm tapping drill for a coarse M16 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.

## Related Pages

[View the full Aluminum Flat Sealing Washers page](https://engineeringhardware.com/fastener/aluminum-flat-sealing-washers-din-7603/)

### More Aluminum Flat Sealing Washers Guides