817M40 Alloy Steel

817M40 817M40T steel suppliers and stockholders. 817M40T is a nickel chrome moly steel supplied in round and flat with delivery to the whole of the UK. It is usually supplied high tensile as 817M40T or 817M40U. This grade is readily machineable and combines good high tensile steel strength with shock resistance, ductility and wear resistance characteristics. In ‘T’ condition it is a widely used engineering steel with a tensile strength of 850-1000N/mm². 817M40T has reasonably good impact properties at low temperatures, whilst it is also suitable for a variety of elevated temperature applications. 817M40T can be flame or induction hardened to give a case hardness of 50HRc or higher.

West Yorkshire Steel are suppliers of 817M40T in diameters and cut flat bar pieces, which can be supplied as sawn blanks to your required sizes.

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

Alternative grades we supply

605M36T | 709M40T  | 708M40T | 826M40W | 835M30 | 535A99 | 655M13 | 722M24 | 905M39

Form of Supply

West Yorkshire Steel are stockholders and suppliers of 817M40T round bar and sawn flat bar and plate – squares, flats and diameters can be sawn cut to your required sizes. Bar is available bright drawn and black hot rolled up to one metre in diameter. 817M40T can be sawn to your required lengths as one offs or multiple cut pieces. 817M40T centreless ground steel bar can be supplied, providing a high tensile engineering steel precision ground bar to tight tolerances.

Click here to contact our experienced sales team who will assist you with your 817M40T steel enquiry.

  • Plate
  • Flat
  • Diameter

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817M40T is a popular high tensile steel used widely in many industries. It is widely used in the plastic and rubber moulding industries for moulds (particularly rubber moulds), hob retaining rings, patens, retaining rings for built up moulds and stop pins for moulds. For moulds applications 817M40 is normally supplied hardened and tempered to ‘T’ condition. If a higher hardness is desired 817M40T should be annealed and heat treated to the required hardness. It is suitable to produce parts for locomotives, cranes, rolling mills, coal cutting machinery etc. where great strength and fatigue resistance are required. Other applications for 817M40 and 817M40T are found in die casting and hot metal working, for example die bolsters, racks and pinions, angle pins for pressure die casting; hot stamping dies for aluminium stamping; die beds for steel stamping; lower temperature nut, bolt and rivet heading dies and large section drop forging dies.

Carbon 0.36-0.44% Nickel 1.30-1.70%
Manganese 0.45-0.70% Chromium 1.00-1.40%
Silicon 0.10-0.35% Molybdenum 0.20-0.35%
Phosphorous 0.035% max
Sulphur 0.040% max

817M40T flat bar is available cut from large rectangular block, pieces can be sawn to your specific sizes.

Preheat the steel carefully, then raise temperature to 1000-1100°C for forging. Do not forge below 850°C. After forging this alloy steel, cool slowly preferably in a furnace.

Heat the 817M40T slowly to 840-860°C, soak well and allow to cool with the furnace to 580°C, before withdrawing.

When parts are heavily machined, ground or otherwise subject to cold work, stress relieving will be beneficial prior to hardening. Heat carefully to 650-670°C, soak well before cooling in the furnace or in the air.

817M40T is commonly supplied ready heat treated. If further heat treatment is required annealed 817M40 should be heated slowly to 830-850°C and after adequate soaking at this temperature quench in oil. Temper as soon as tools reach room temperature. Hardening from a neutral salt bath, will reduce the possibility of scaling or decarburisation. Heat to 830-850°C and after equalisation quench in oil.

Heat the steel carefully to a suitable temperature selected by reference to a tempering chart or table, soak at the temperature for two hours per 25mm of ruling section, then all to cool in the air. Tempering between 250-375°C is not advised as tempering within this range will reduce the impact value.

Condition Tensile
T 850-1000 650 13 35 248-302
U 925-1075 755 12 42 269-331
V 1000-1150 850 12 42 293-352
W 1075-1225 940 11 35 311-375
X 1150-1300 1020 10 28 341-401
Y 1225-1375 1095 10 21 363-429
Z 1550 1235 5 9 444

(*subject to ruling section)

Heat treatment temperatures, including rate of heating, cooling and soaking times will vary due to factors such as the shape and size of each steel component. Other considerations during the heat treatment process include the type of furnace, quenching medium and work piece transfer facilities. Please consult your heat treatment provider for full guidance on heat treatment of alloy steel.

817M40T alloy steel is available with a cast and analysis certificate or BS EN 10204 3.1 mill certificate, please request when placing any orders.

817M40T is supplied in accordance with our ISO 9001:2015 registration.