Key Steel


Key steel stockholders and suppliers, delivering to the whole of the UK. A bright drawn steel in square and rectangular bar, key steel is an unalloyed medium carbon steel with reasonable tensile strength. It is supplied bright drawn in flat and square sections conforming to the specification requirements of BS46 and BS4235.

Imperial sizes of key steel bar are bright drawn to plus tolerances conforming to BS46 “keys and keyways”. Metric sizes of key steel bar are bright drawn to minus tolerances conforming to BS4235 “parallel and taper keys”.

We welcome export enquiries for key steel. Contact our sales office and consult our shipping policy for further details.

Form of Supply

As key steel suppliers West Yorkshire Steel offer rectangular and square bar in 1 metre and 3 metre lengths. Key Steel is a bright drawn carbon steel available in standard metric and imperial sizes (listed at bottom of this page).

  • Flat

Click on the headings below for further information

Applications

Key Steel is widely used for many general engineering applications. Typical key steel applications include taper, gibhead, plain and parallel keys.


Carbon 0.35-0.45% Phosphorous 0.06% max
Manganese 0.60-1.00% Sulphur 0.06% max
Silicon 0.05-0.35%

As a bright drawn steel bar it is uncommon to harden key steel. In its supply condition key steel has an approximate tensile strength of 500 to 700N/mm2.

If heat treatment is a requirement, key steel can be heat treated by conventional methods and flame or induction hardening. Please consult your heat treatment provider for full guidance on heat treatment of key steel.


Imperial Squares
Up to and including 7/8” -0/+0.002”
Over 7/8” Up to and inc. 1 ¼” -0/+0.003”
Over 1 ¼” -0/+0.004″
Imperial Flats  
Up to and inc. ¾” x ½” Width -0/+0.002”   Thickness -0/+0.003”
⅞” x ⅝” Width -0/+0.002”   Thickness -0/+0.004”
Over ⅞” x ⅝”” up to and inc. 1¼” x ⅞” Width -0/+0.003”   Thickness -0/+0.004”
Over 1¼” x ⅞” up to and inc.1¾” x 1¼” Width -0/+0.004”   Thickness -0/+0.006”
2″ x 1 1/4″ Width -0/+0.005”   Thickness -0/+0.006”
Metric Squares (mm)
Up to and inc. 6 +0mm/-0.030mm
Over 6 and up to and inc. 12 +0mm/-0.036mm
over 16 +0mm/-0.043mm~
Metric Flats  
8 x 7 up to and inc. 10 x 8 Width +0/-0.036mm   Thickness +0/-0.090mm
Over 10 x 8 up to and inc. 16 x 10 Width +0/-0.043mm   Thickness +0/-0.090mm
18 x 11 Width +0/-0.043mm   Thickness +0/-0.110mm
Over 18 x 11 up to and inc. 28 x 16 Width +0/-0.052mm   Thickness +0/-0.110mm
32 x 18 Width +0/-0.062mm   Thickness +0/-0.110mm
Over 32 x 18 up to and inc. 50 x 28 Width +0/-0.062mm   Thickness +0/-0.130mm

Imperial Sizes Metric Sizes
3/16″ sq 5/8″ sq 4mm sq 16mm x 28mm
3/16″ x 1/4″ 5/8″ x 3/4″ 5mm sq 18mm x 32mm
1/4″ x 5/16″ 5/8″ x 7/8″ 6mm sq 20mm sq
1/4″ sq 5/8″ x 1″ 6mm x 10mm 20mm x 25mm
1/4″ x 3/8″ 3/4″ sq 7mm x 8mm 20mm x 36mm
1/4″ x 1/2″ 3/4″ x 7/8″ 8mm sq 22mm sq
1/4″ x 5/8″ 3/4″ x 1″ 16mm x 20mm 22mm x 40mm
5/16″ sq 3/4″ x 1 1/4″ 8mm x 12mm 24mm sq
5/16″ x 3/8″ 7/8″ sq 9mm x 14mm 25mm sq
5/16″ x 7/16″ 7/8″ x 1″ 10mm sq 25mm x 40mm
5/16″ x 1/2″ 7/8″ x 1 1/2″ 10mm x 12mm 25mm x 45mm
3/8″ sq 1″ sq 10mm x 16mm 28mm sq
3/8″ x 7/16″ 1″ x 1 1/4″ 11mm x 18mm 28mm x 50mm
3/8″ x 1/2″ 1″ x 1 1/2″ 12mm sq 30mm sq
3/8″ x 5/8″ 1″ x 1 5/8″ 12mm x 20mm 32mm x 56mm
9/16″ sq 1 1/8″ sq 14mm sq 32mm sq
7/16″ sq 1 1/4″ sq 14mm x 22mm 36mm sq
7/16″ x 5/8″ 1 1/4″ x 1 3/4″ 14mm x 25mm 38mm sq
1/2″ sq 1 1/4″ x 2″ 15mm sq 40mm sq
1/2″ x 5/8″ 1 1/2″ sq 16mm sq 45mm sq
1/2″ x 3/4″ 1 1/2″ x 2″ 8mm x 10mm 50mm sq
1/2″ x 1″ 1 3/4″ sq
3/8″ x 3/4″ 1 3/4″ x 2″
2″ sq

We recommend you contact your welding consumables supplier who should provide you full assistance and information on welding key steel.


Key Steel is available with a certificate of conformity, if required please request when placing any orders.


Key Steel bar is supplied in accordance with our ISO 9001 : 2008 registration.