What is 4140 /EN19 round bars ?

4140 / EN19 round bars are high-strength, low-alloy steel products widely valued in the engineering, automotive, and oil & gas industries for their excellent combination of toughness, wear resistance, and fatigue strength. Known under different standards—AISI 4140 in the American system, EN19 in the British standard (BS 970), DIN 42CrMo4 in Europe, and JIS SCM440 in Japan—this steel grade is recognized globally for its reliability and performance in demanding applications. Its composition typically includes carbon, chromium, molybdenum, and manganese, which together offer high tensile strength, good hardenability, and the ability to withstand high stress without failure.

One of the key strengths of 4140 / EN19 round bars lies in their versatility in heat treatment. They can be supplied in annealed condition for ease of machining, normalized for improved mechanical properties, or quenched and tempered to achieve high strength and hardness while maintaining toughness. In quenched and tempered condition, hardness levels can reach up to 55 HRC, making them suitable for high-wear applications. This adaptability allows engineers to tailor the steel’s properties for specific operational requirements without compromising structural integrity.


These round bars are commonly used in the manufacturing of components such as gears, shafts, axles, crankshafts, connecting rods, heavy-duty bolts, and couplings. In the oilfield sector, they are often used for drill collars, tool joints, and other high-strength parts that require exceptional resistance to impact and wear. Their ability to maintain performance under high loads and repeated stress cycles makes them a popular choice for critical rotating or load-bearing parts.

Material Specification Chart of 4140 Round Bar

Specifications ASTM A182, ASME SA182
Standards EN, DIN, JIS, ASTM, BS, ASME, AISI
Range of Diameter 5mm to 500mm
Finish Bright, Black, Forged, Turned Bright
Length 1000 mm Long To 6000 mm Long
Form Round, Billet, Ingot, Forging Etc.

SAE 4140/ EN19 / 42crmo4 Round Bars Grade

Country names India USA German British Japan China Australia
Country standards UNS AISI ASTM A29 DIN 17200 BS 970 JIS G4105 GB/T 3077 AS 1444
Grades G41400 4140 4140 1.7225/ 42CrMo4 EN 19 / 42CrMo4 SCM440 42CrMo 4140

4140 / EN19 round bars combine machinability, durability, and high mechanical performance in one steel grade, making them a staple for heavy-duty industrial use. Whether in automotive drive components, industrial machinery, or oilfield equipment, they deliver the reliability and long service life that engineers and manufacturers demand. With the right heat treatment and machining, these bars can meet both standard and highly specialized application needs.



We also proudly serve as a reliable 4140 round bar supplier in South Africa, meeting the requirements of mining and heavy equipment industries. With a commitment to customer satisfaction, technical expertise, and stringent quality control, Super Metal Manufacturing Co. continues to be a globally trusted source for alloy steel round bars. Whether you’re in need of rough stock or precision-cut components, we offer the right solution tailored to your industry.

Choose Super Metal Manufacturing Co. as your preferred 4140 round bar supplier in Saudi Arabia, Qatar, UAE, Spain, Oman, Japan, Germany, United States, United Kingdom, South Korea, and South Africa — where quality meets performance and delivery meets expectations.


Alloy Steel 4140 Round Bars Dimensions Standard

Diameter or
Width
(mm)		 Weight per meter Sectional Area Perimeter
Round
(kg)		 Round
(cm²)		 Round
(cm)
5.0 0.15 0.20 1.57
5.5 0.19 0.24 1.78
6.0 0.22 0.28 1.88
7.0 0.30 0.38 2.20
8.0 0.39 0.50 2.51
9.0 0.50 0.64 2.83
10 0.63 0.79 3.14
11 0.75 0.95 3.46
12 0.89 1.13 3.77
14 1.21 1.54 4.40
16 1.58 2.01 5.03
18 2.00 2.54 5.65
20 2.47 3.14 6.28
22 2.98 3.80 6.91
25 3.85 4.91 7.85
28 4.83 6.16 8.80
32 6.31 8.04 10.05
36 7.99 10.18 11.31
40 9.86 12.57 12.57
45 12.49 15.90 14.14
50 15.41 19.64 15.71
56 19.34 24.63 17.59
63 24.47 31.17 19.79
71 31.08 39.59 22.31
80 39.46 50.27 25.13

Application of AISI Alloy Steel 4140 Round Bars

ASTM alloy 4140 steel bar, flat or plate material can be used for as wide variety of applications where greater toughness and wear resistance is needed over lower carbon grades. Typical applications for 4140 tool steel uses include Components, Adapters, Arbors,strippers, holder blocks, mold bases, ejectors, back up and support tooling, fixtures, jigs, molds, cams, drill collars, Axle Shafts, Bolts, Crankshafts,stubs, couplings, reamer bodies, axles, shafting, piston rods, rams, hydraulic machinery shafts, gears, sprockets, gear racks, chain links, spindles, tool bodies, tool holders, tie rods, Connection Rods, Chuck Bodies, Collets, Conveyor Pins & Rolls, Ejector Pins, Forks, Gears, Guide Rods, Hydraulic Shafts & Parts,Lathe Spindles, Logging Parts, Milling Spindles, Motor Shafts, Nuts, Pinch Bars, Pinions, Pump Shafts,boring bars,tracks, slides, wear strips or parts, forming dies, brake dies, trim dies, bolsters, machinery parts and components, etc.

Countries we have exported our products to:

Turkey, Thailand, Bulgaria, Serbia, Mexico, Estonia, Trinidad & Tobago,Tunisia, New Zealand, Indonesia, Puerto Rico, Ireland, India, Morocco, Brazil, Lebanon, Hong Kong, Jordan, Ukraine, Switzerland, Czech Republic, Lithuania, Sri Lanka, Greece, Taiwan, Zimbabwe, Algeria, Romania, Mexico, Ghana, Italy, Philippines, Spain, United Kingdom, Finland, Azerbaijan, Japan, Macau, Israel, Saudi Arabia, Kenya, Bhutan, Poland, Poland, Costa Rica, Kuwait, Singapore, Pakistan, France, Colombia, Tibet, Bolivia, Portugal, Iraq, Australia, Kazakhstan, Nepal, Mongolia, Gambia, Malaysia, Chile, Germany, Slovakia, China, Bahrain, Denmark, Angola, Afghanistan, Peru, Austria, Ecuador, Gabon, Croatia, South Africa, Sweden, Chile, Hungary, United Arab Emirates, Argentina, Bangladesh, Oman, Egypt, United States, Belgium, Canada, Namibia, Norway, Qatar, Belarus, Netherlands.

Cities we have supplied our products to:

Bengaluru, Vung Tau, Nashik, Jaipur, Navi Mumbai, La Victoria, Al Jubail, Noida, Granada, Doha, Dammam, Ernakulam, Chandigarh, Santiago, Melbourne, Surat, Nagpur, Ranchi, Kanpur, Jakarta, Ahvaz, Indore, Jamshedpur, Muscat, Rajkot, Lahore, Chiyoda, Milan, Hong Kong, Riyadh, Houston, Busan, Calgary, Madrid, Visakhapatnam, Atyrau, Bhopal, Algiers, Colombo, Kolkata, Petaling Jaya, Dallas, London, Cairo, Thiruvananthapuram, Caracas, Howrah, Moscow, Port-of-Spain, Baroda, Mexico City, Gurgaon, Singapore, Aberdeen, Coimbatore, Kuala Lumpur, Perth, Ahmedabad, New York, New Delhi, Manama, Abu Dhabi, Montreal, Jeddah, Pune, Vadodara, Kuwait City, Chennai, Geoje-si, Tehran, Mumbai, Hanoi, Karachi, Pimpri-Chinchwad, Thane, Haryana, Ulsan, Seoul, Dubai, Ho Chi Minh City, Toronto, Hyderabad, Los Angeles, Faridabad, Lagos, Sydney, Courbevoie, Bangkok, Bogota, Rio de Janeiro, Ankara, Al Khobar, Ludhiana, Istanbul, Gimhae-si, Brisbane, Edmonton, Sharjah, Secunderabad.