This chart is provided to help compare common materials and their uses, giving details of specific properties that destinguish one metal type from another. The information given is provided from experience gained over many uses and applications. Material make-up detailing actual tensile strength and elongation can be provided if requested.
Mild Steel that is very easy to machine to a good surface finish, it contains a percentage of lead which makes it unsuitable for welding. It is most commonly used in mass produced (CNC) items because of the ease of which it machines which aids extended tool life.
Common uses: Low stress hubs, casings, handles, linkages and shafts.
Not suitable for: Stressed items subjected to tensile loading such as bolts, studs or wear likely applications as the surface will tend to dull and 'pick up' onto mating materials. Material rusts very readily if left unprotected. Although this steel can be welded, it is not recommended as the parent material will tend to 'rip' about the welds when stressed, shear loading will cause failour.
Machining: To achive the best finish and accuracy, EN1A should be machined at high surface speeds and feeds with a general purpose carbide tool, HSS can be used to good effect. Most lubricants are suitable, but beware that cutting oils will cause surface staining.
Mild Steel, fairly easy to machine but with a tendency to 'rip' if unlubricated. It is very easy to weld and is used as a more general purpose steel for multiple applications.
Common uses: Lightly stressed bolts, fixings, shafts, spacers, hubs and bushings. Bracketry, linkages and baseplates would be fine to produce using EN3.
Not suitable for: Stress components such as torque loaded shafts, high bending forces and shock loading. The material will yield and distort under stress conditions, bending before shear.
Machining: Surface 'ripping' is more evident in EN3 so lubrication is essential. Fairly high surface speeds should be used with moderate feeds. Screwcutting is easy with cutting oil and achiving a fine finish is achived with slight polishing. Very nice to weld with good flow and strength.
Medium strength steel that is suitable where good all-round performance is required. Much better quality than EN3 but with the drawback of machinability.
Common uses: Hydraulic rams (chromed) , key steel, medium torqued shafts, medium bending and compression loading applications. Good corrosion resistance. Material bends considerably before failour.
Not suitable for: High shock loads as the material tends to shear under extreme conditions. High bending forces.
Machining: Achiving a fine finish is more difficult because the material tends to 'rip', especially evident during fine pitch dry screwcutting. Plenty of high oil content lubricant is recommended. Final polishing is very likely required to gain a fine finish though will never quite look as bright as EN3. Welding is very easy and achives a strong joint.
High strength steel that shares many of the good mechanical properties of EN8 but is far more resistant to shear loading and frictional wearing.
Common uses: Tolerant shear pins, connecting rods, crossheads, pistons, high load couplings and hubs. Resists shearing and bending but with plenty of 'give' before breakage.
Not suitable for: EN16 is a very good 'all round' performer, with the exception of material cost to hold against it. May be used in most higher loading or shock applications.
Machining: The material is very similar to machine as EN8, showing a reluctance to polish to a bright finish and has a very slight golden colour to the surface which develops over time. Screwcutting is fairly easy with less ripping than EN8, though copious quantities of high pressure cutting fluid is recommended to achive the best surface.
High strength steel to be used when a very high tolerance to shock loading is required, suitable to be used in areas of very high loading such as gear boxes etc. Material has slight corrosion resistant properties and is possible to machine very accuratly to a fine surface finish. Can be induction hardened.
Common uses: Tow pins, high load studding, gears, shafts, racks, pawls and load bearing tie rods.
Not suitable for: Suitable for most applications where strength is the main requirement, but higher material cost should be considered.
Machining: Quite tough material to machine as turning can be long and string like, especially with HSS cutters - though the application of plenty of coolant aids tool life. Easy to obtain a high surface finish with carbide tipped tools and should be machined at a medium surface speed. Polishes very well and easy to machine to fine dimensional tolerances. Generally a stainless grade of carbide should be used if possible.
Very high strength steel that is easy to thru' heat treat and temper with minimum surface scaling.
Common uses: Used for the production of punches and dies because of its hardenability, drill bushings, bearings surfaces, high strength shafts, gears, hubs, screws and fixings.
Not suitable for: Shock shear loading is more limited than EN19 to EN16 because failour will be more likey to occur in shear loads. Cracking and distortion can occur during heat treatment so sharp edges should be rounded where possible.
Machining: Tough to machine, especially with HSS. The use of carbide is recommended - though chip breaking is easilly achived with moderate tool feeds. Easy to produce a high quality surface finish to high tolerances and higher surface speeds can be used on final cuts. Best roughed out at a slower speed but higher feed then finished with high speed and moderate feeds. Can be machined when hardened with stainless grade tips or ceramics.
To be used very high surface strength is required with a softer core material.
Common uses: High quality crank shafts, high strength gearing, shafts, dogs and couplings. Maintains a soft core after heat treatment to resist shear whilst a very hard surface will aid friction mechanical faces.
Not suitable for: Material is produced for high strength, cost would be an issue when selecting its use.
Machining: In un-heat treated state the material machines similar to other tool steels but with a slight dulling to the surface when compared to such as EN19 or similar. After heat treatment, surface grinding should be performed to clean mechanical faces as scale can be quite previlant. Ceramic tips may be used with high surface speeds.