Cold Finished Carbon Steel Bars Machining
Cold finished carbon bars are produced from Special Bar Quality Rolled Bars by cold drawing, turning or grinding or by a combination of these methods. The cross sectional area of the hot rolled bar is cold reduced, resulting in accurate size, smooth surface, increased mechanical properties and machinability.
12L14 is considered to be one of the fastest machining steels currently produced. This has been achieved through the addition and even dispersal of tony lead particles throughout the bar. C12L14 gives a smooth, machined surface and because of its low friction component allows increased tool life. This grade is recommended for high-speed automatic screw machine parts.
1215 is one of the most popular screw stocks marketed today. C1215 provides good surface finish and brazing properties.
1018 is a general purpose low carbon steel with good case hardening qualities. It is especially suited to cold forming and bending operations. Material is suitable for parts which require cold forming (such as crimping, swaging, or bending). For severe bends, however, stress relieving may be necessary to prevent cracking.
1045 is a medium carbon steel used extensively in induction hardening applications. This is not normally considered a screw machine steel and is only fair for brazing and welding. However, it can be forged satisfactorily and is the most common shafting steel in the medium carbon range.
1117 is a low carbon, high manganese steel. Machinability is improved over 1018, and case hardening is deep and uniform, supported by a tough ductile core.
11L17 is a resulphurized steel with good machinability and surface finish. The product is made much the same way as 12L14 where the lead does not alloy with the steel. Lead is retained in its elemental state and us dispersed within the steel’s structure allowing chips to break off easier during machining.
1141 is a medium carbon, special quality, manganese steel, with an improved machinability and better heat treatment response. Surface hardness is deeper and more uniform than plain carbon steels.
1144 is a resulphurized carbon steel containing manganese and sulphur to provide a free-machining steel. It is recommended especially for high-production automatic machine products and machined parts requiring higher strength and wear resistance than is possible with lower carbon steels.
Stressproof is a medium carbon free machining steel that has been severely cold reduced to improve its mechanical properties. Its inherent strength, without heat treatment, is a comparable to heat treated steels of equal hardness. This permits direct use of many parts following the last machining operation, without the necessity of a further hardening treatment.
Specialty Alloys Machining
This medium carbon alloy grade is widely used for many general purpose parts requiring high tensile strength and toughness. 4140 contains chromium and molybdenum as alloying elements and may be heat treated over a wide range to give the combined advantages of proper hardness, strength and ductility. In conditions where localized hardness may be required, this steel is ready flame or induction hardened.
Carefully controlled proportions of chromium, nickel and molybdenum are responsible for the extensive use of 8620 as a carburizing alloy steel. Valuable features of this grade include extreme surface hardenability and internal strength.
Stainless Steel Machining
Grade 303 is a free machining variation of 304. The addition of sulfur for better machinability makes this a favorite for use in automatic screw machines. Corrosion resistant to atmospheric exposures, as well as a wide range of chemicals; most dies, foods and nitric acid.
Grade 304/304L is the most widely used of the austenitic grades, 304 offers good corrosion resistance too many chemicals and industrial atmospheres. Generally considered non-magnetic, it can become slightly magnetic when cold worked. 304 is non-hardenable by heat treatment. In 304L, the carbon content has been lowered to .03% max. for corrosion resistance at heat affected zones from welding.
Grade 316 is an austenitic chrome nickel steel with superior corrosion resistance to that of other chrome nickel steels. Widely used when exposed to chemicals corrodents, as well as marine atmospheres. 316 is generally considered non-magnetic, but can become magnetic when cold worked. In 316L, the carbon content has been lowered to .03% max. for corrosion resistance at heat-affected zones from welding.
Grade 416 is a martensitic chromium steel to which elements have been added to enhance the machinability. 416 is the most readily machinable of all the stainless steel and is suitable for use an automatic screw machines. 416 is less corrosion resistant than chrome-nickel steels. It is magnetic in all conditions.
360 Half Hard
360 Free Machine Brass is a soft, ductile metal that machines quite easily. It is utilized in general screw machine applications as well as high volume production. 360 excellent machinability rating of 100%, allows it to be used at the highest capacities of any screw machine work. Typical applications include: plumbing products, fittings, adapters, valve stems, and miscellaneous screw machine parts.
This free machining alloy compares favorably with free cutting brass. It is the most suitable alloy for machining on automatic, milling machines, lathes, planers, sharpers and other machine tools, and is the most widely used alloy for all types of screw machine parts. It can be machined at high speeds and comparatively heavy feeds. Machined surfaces are bright and smooth. Mechanical finishes readily match joined parts. Mechanical properties and hardness are excellent; corrosion resistance fair. Weldability by resistance method is fair; other welding is not recommended.
One of the strongest of heat treatable alloys, 2014 is used in heavy duty applications. Machinability is good to excellent when high rakes and clearances, adequate coolant, sharp tools, fast speeds, and light to medium cuts and feeds are employed. Machined services are very smooth. Weldability is good with arc and resistance methods. Corrosion resistance is fair. This is the most widely used forging alloy.
Like 2011, this is also a general purpose alloy for automatic screw machine work. It is stronger than 2011, but harder to machine and does not have the fine chip associated with 2011. It is recommended for heavy duty parts because of its high strength. Workability is fair, with ductility and formability considered better than 2014. Arc and resistance weldability are satisfactory. Corrosion resistance is fair. It is used for rivets, fasteners, and aircraft components.
Known as the "aircraft alloy" in machining rod, this alloy has properties higher than 2017 and 2014. Deformability is generally considered only fair in the cold state, it is one of the most popular alloys for cold heading and roll threading applications. Can be machined to a high finish. Corrosion resistance is fair. Applications include Phillips head screws, wood screws, hydraulic fittings and small parts in clocks and meters. It is also the basic alloy for cold finished rectangular bar where strength and machinability are essential for precision fittings and parts.
Generally selected where welding or brazing is required, or for its particularly high corrosion resistance in all tempers. Formability is excellent in 0 temper, good in T4. Machining is more difficult than with other machining alloys; it is particularly gummy in 0 condition, fair in hard tempers. Corrosion resistance and appearance after anodizing are highest of screw machine alloys, the properties are generally lower. Applications include railway car components, bridge components, pipe fittings, wheels in various transportation and uses.
Has excellent machinability, is readily welded, and has good corrosion resistance. Formability is fair in T6 temper, difficult in T9. Bright, smooth finish is easy to obtain.
Hot and Cold Forgings Machining