Manufacturer, Supplier & Exporter of Hardened & Tempered Round Bar

Hardened & Tempered Round Bar is a high-strength engineering product widely used across demanding sectors where superior hardness, durability, and wear resistance are essential. These bars undergo a controlled heat-treatment process involving hardening followed by tempering, which significantly enhances their mechanical strength and toughness. Riddhi Siddhi Impex is a leading manufacturer and supplier of premium-quality Hardened & Tempered Round Bars crafted to meet Indian and international industrial standards..

The hardening process increases the tensile strength and wear resistance of the steel, making these bars suitable for high-stress applications. Tempering, on the other hand, improves ductility and reduces brittleness, ensuring long-term performance even under fluctuating load conditions. This combination makes the bars ideal for mechanical parts that require optimum balance between strength and toughness.

Riddhi Siddhi Impex manufactures these round bars in various grades and sizes to suit diverse engineering applications. The bars are produced using high-quality alloy steels, carbon steels, or tool steels depending on the requirement. Strict quality inspection, ultrasonic testing, and dimensional accuracy ensure that every bar meets stringent industry standards...

Hardened & Tempered Round Bars are widely used in components such as shafts, spindles, bolts, connecting rods, axles, tools, fasteners, and wear-resistant machine parts. Their superior load-carrying capability and fatigue resistance make them ideal for industries such as automotive, machinery manufacturing, mining, cement plants, oil & gas equipment, and heavy engineering...

We supply Hardened & Tempered Round Bars in cities including Mumbai, Delhi, Bengaluru (Bangalore), Hyderabad, Chennai, Kolkata, Pune, Ahmedabad, Surat, Vadodara, Rajkot, Nagpur, Indore, Bhopal, Jaipur, Kanpur, Lucknow, Agra, Varanasi, Amritsar, Chandigarh, Mysuru, Udaipur, Jodhpur, Visakhapatnam, Coimbatore, Madurai, Kochi, Thiruvananthapuram, Mangalore, Nashik, Kolhapur, Chandrapur, Akola, Vilayat, Somnath, Dahej, Narmada, Ankleshwar, Navsari, Valsad, Rajpipla, and many other industrial zones..

Hardened & Tempered Round Bar – Technical Details

1. Specification

Property	Details
Product	Hardened & Tempered Round Bar
Diameter Range	10 mm – 300 mm
Length	1 Meter – 6 Meter (Custom Available)
Hardness	28 HRC – 55 HRC
Surface Finish	Black, Bright, Polished
Heat Treatment	Hardening + Tempering
Grades Available	EN8, EN9, EN19, EN24, 4140, 42CrMo4, C45, C55
Manufacturing Process	Hot Rolled, Forged, Normalized, Heat Treated

2. Chemical Composition

Element	Percentage (%)
Carbon (C)	0.28 – 0.60
Manganese (Mn)	0.60 – 1.50
Silicon (Si)	0.10 – 0.40
Chromium (Cr)	0.80 – 1.50
Molybdenum (Mo)	0.15 – 0.40
Phosphorus (P)	≤ 0.040
Sulphur (S)	≤ 0.040

3. Mechanical Properties

Mechanical Property	Value
Tensile Strength	700 – 1100 MPa
Yield Strength	450 – 850 MPa
Hardness	28 – 55 HRC
Elongation	10 – 18%
Impact Strength	55 – 80 Joules

4. Dimension Chart

Diameter (mm)	Weight (kg/m)
10	0.62
20	2.47
30	5.55
40	9.85
50	15.41
60	22.20
80	39.46
100	61.75
150	139.00
200	246.00

5. Equivalent Grades

Material	Equivalent Grade
EN8	C40, AISI 1040
EN9	C55, AISI 1055
EN19	AISI 4140, 42CrMo4
EN24	AISI 4340, DIN 1.6511

6. Equivalent Standards

Standard	Description
ASTM	American Standard (A29 / A322)
EN	European Standard (EN10083, EN10277)
DIN	German Standard (DIN 17200)
JIS	Japanese Standard (JIS G4051)
BIS	Indian Standard (IS 1570)

7. Other Types of Round Bars

Type
Annealed Round Bar
Normalized Round Bar
Quenched & Tempered Round Bar
Induction Hardened Bar
Precision Ground Shaft Bar
Case Hardened Alloy Bar

These bars are produced with tight dimensional tolerance, uniform hardness, excellent machinability, and high surface finish. Their consistent metallurgical structure makes them suitable for machining, forging, CNC processing, and high-precision manufacturing. The bars also exhibit excellent performance under thermal stress due to their tempered microstructure..

Frequently Asked Questions (FAQs)

Q1: What is a Hardened & Tempered Round Bar?

It is a heat-treated alloy or carbon steel bar processed through hardening and tempering to increase strength, durability, and impact resistance.

Q2: What hardness range is available?

Riddhi Siddhi Impex supplies bars with hardness ranging from 28 HRC to 55 HRC.

Q3: Which industries use these bars?

Widely used in automotive, mining, gear manufacturing, shafting, machinery parts, and construction equipment.

Q4: Do you provide custom lengths?

Yes, custom cut-length bars are available based on client requirements.