Hunan ShunFu Metal Material Co., Ltd.

PRODUCTS

Rock Hollow Steel

We pride ourselves on providing high-quality steel that meets the rigorous demands of the drilling industry. Our commitment to innovation and quality ensures that our clients receive the best materials for their tools, contributing directly to their operational success.

rock hollow drill hexagon steel bar
rock hollow drill round steel bar
Why Choose Us

Advantages

Our drill steels for efficient, economical production and longer service life!

High fatigue strength and toughness

High resistance to wear and permanent distortion

Properties that enable efficient and economic production

Close tolerances for automated manufacturing process

A uniform response to heat treatment

Uniform straightness, eliminating the need for straightening

Our Standards

Product Quality

1

Raw Material Selection

Product quality begins at the very start of the process, where raw material is carefully selected for melting in our 75 tonnes electric arc furnace.

2

Continuous Bloom Casting

The continuous, three stand bloom caster gives us several quality advantages compared to ingot casting — including superior control of:

✦  Non-metallic inclusions    ✦  Purity
✦  Material structure    ✦  Surface finish

3

Drilling & Core Insertion

Long-hole drilling and the insertion of a core in the drill steel blank, prior to rolling, produce straight centre holes with close dimensional tolerances. After rolling, the core is withdrawn.

4

Surface Turning

In order to eliminate decarburisation and other defects, the surface is turned before the final rolling process — ensuring a clean, defect-free finish.

5

Controlled Cooling Process

After rolling, a carefully controlled cooling process guarantees the final and uniform mechanical properties throughout the bar.

Steel Grades

Our Products

Sanbar 20

95CrMo

A high strength chromium-molybdenum steel with high fatigue strength and excellent wear resistance in the as-rolled condition.

Application

Integral drill steels primarily (pilot rods and tapered rods).

Mechanical Properties

Tensile Strength ≥1300 MPa (189 ksi)
Yield Strength ≥850 MPa (123 ksi)
Hardness 37 – 43 HRC

Sanbar 23

High Chromium Molybdenum Alloy Steel

An air hardening, high chromium, molybdenum alloy steel with good response to surface induction hardening, suitable for carburising. High fatigue strength and wear resistance in the case hardened condition.

Application

Extension rods, shank rods, (tapered rods).

Mechanical Properties

Tensile Strength ≥1350 MPa (189 ksi)
Yield Strength ≥1000 MPa (123 ksi)
Hardness 38 – 44 HRC

Sanbar 61

40SiMnCrNiMo

A high strength silicon steel with good toughness and impact resistance in the as-rolled condition.

Application

Tapered rods primarily (pilot rods and integral drill steels).

Mechanical Properties

Tensile Strength ≥1350 MPa (189 ksi)
Yield Strength ≥820 MPa (123 ksi)
Hardness 38 – 44 HRC

Sanbar 64

23CrNi3Mo

An air-hardening, high nickel alloy steel with good response to carburising. Excellent fatigue strength and wear resistance in the case hardened condition.

Application

Extension rods, shank rods, (tapered rods).

Mechanical Properties

Tensile Strength ≥1250 MPa (189 ksi)
Yield Strength ≥900 MPa (123 ksi)
Hardness 37 – 44 HRC
Technical Data

Chemical Composition

All values shown as weight percentage (%) — typical nominal composition

Steel Grade C Mn Si Ni Cr Mo V
95CrMo SANBAR 20 0.90–1.00 0.15–0.40 0.15–0.40 0.80–1.20 0.15–0.30
SANBAR 23 0.24 0.5 0.3 3.1 0.5
40SiMnCrNiMo SANBAR 61 0.37–0.43 0.80–1.10 1.30–1.60 0.40–0.60 0.60–0.90 0.20–0.40
23CrNi3Mo SANBAR 64 0.19–0.26 0.55–0.75 0.15–0.35 2.75–3.10 1.15–1.45 0.20–0.30
55SiMnMo 0.50–0.60 0.60–0.90 1.10–1.40 0.40–0.55
35SiMnMoV 0.32–0.41 1.30–1.60 0.60–0.90 0.40–0.60 0.07–0.15
80Cr 0.75–0.85 ≤0.35 ≤0.35 1.40–1.65 ≤0.15
24SiMnCrNi2Mo FF710 0.21–0.27 1.20–1.50 1.30–1.70 1.65–2.00 0.25–0.35 0.30–0.40
Hover to highlight row
 Not applicable / not specified
Specifications

Dimensions

Other sizes are available on request.  H = Hexagon  |  R = Round

Hexagonal Hollow Steel

Metric Units (mm / kg/m)
Type Counter Diameter Hole Diameter Eccentricity
(mm)
r
(mm)
Weight
(kg/m)
size (mm) tolerance (mm) size (mm) tolerance (mm)
H19 19.0
+0.3−0.2
6.0
+0.7−0.8
0.52.52.21
H22 22.2
+0.3−0.2
6.7
+0.7−0.8
0.63.03.05
H25 25.3
+0.4−0.2
7.6
+0.8−0.7
0.73.03.97
H28 28.6
+0.5−0.3
8.8
+0.8−0.7
0.83.55.05
H32 32.1
+0.6−0.2
9.5
+0.8−0.7
0.94.06.36
H35 35.3
+0.6−0.3
9.5
+0.8−0.6
1.04.07.86

Round Drill Steel

Metric Units (mm / kg/m)
Type Outside Diameter Hole Diameter Eccentricity
(mm)
Weight
(kg/m)
size (mm) tolerance (mm) size (mm) tolerance (mm)
R32 32.2
+0.7−0.3
9.2
+0.8−0.8
0.75.83
R39− 39.0
+0.8−0.3
13.0
+1.2−1.2
1.08.27
R39 39.0
+0.8−0.3
14.5
+1.2−1.2
1.08.02
R46− 45.8
+0.8−0.3
15.0
+1.5−1.2
1.211.46
R46 45.8
+0.8−0.3
17.0
+1.5−1.2
1.211.07
R52− 52.0
+1.0−0.0
19.0
+1.5−1.2
1.414.35
R52 52.25
+1.0−0.0
21.5
+1.5−1.2
1.413.72

Sizes and Tolerances

Imperial Units (inch / lb/ft)
Denomination Nominal Bar Size (inch) Tolerance (inch) Hole Dia. incl. Ovality (inch) Eccentricity¹ max (inch) Random² Length ft (±10%) Weight (lb/ft)
H 7/8 0.872
+0.007−0.006
0.263 ± 0.0150.02324.6 – 27.82.05
H 1 0.996
+0.011−0.005
0.338 ± 0.0190.02724.6 – 27.82.60
H 1 1/8 1.125
± 0.009
0.346 ± 0.0190.02718.0 – 21.33.39
H 1 1/4 1.261
+0.013−0.009
0.377 ± 0.0230.03126.2 – 29.54.28
H 1 1/4 1.261
+0.013−0.009
0.476 ± 0.0270.03127.8 – 31.14.06
H 1 3/8 1.389
± 0.011
0.374 ± 0.0230.03929.5 – 32.85.29
H 1 1/2 1.507
± 0.013
0.629 ± 0.0310.03929.5 – 32.85.61
R 1 1/4 1.267
± 0.011
0.362 ± 0.0190.02929.5 – 32.83.94
R 1 1/4 1.267
± 0.011
0.460 ± 0.0230.02924.6 – 27.83.72
R 1 1/2 1.535
± 0.011
0.405 ± 0.0230.03119.6 – 22.95.85
R 1 1/2 1.535
± 0.011
0.570 ± 0.0310.03919.6 – 22.95.42
R 1 3/4 1.803
± 0.015
0.669 ± 0.0350.04732.8 – 36.07.48
R 2 1/32 2.049
± 0.017
0.846 ± 0.0390.06222.9 – 26.29.29
R 2 23/64 2.362
± 0.027
0.889 ± 0.0860.06822.9 – 26.212.78

¹ Eccentricity = the distance between the centre of the bar and the centre of the hole.

² Fixed cut lengths are available on request.

Product Details

Supply Specifications

Forms of Supply

Rock drill steel is supplied as hollow, hot-rolled, round or hexagon bar. The ends are trimmed square to within 0.15 mm (0.006 in) maximum. The outer surface can be supplied dry or oiled for protection against corrosion during transport. The flushing holes are normally sealed with plastic caps. Bars are supplied in standard bundles containing max 1,500 kg (3,300 lbs).

Surface Condition

Both outer and inner surfaces are free from harmful slag marks, cracks and scratches. Maximum depth of defects:

Outer surface ≤ 0.20 mm (0.008 in) Inner surface ≤ 0.15 mm (0.006 in)

Straightness

Maximum deviation is:

1 mm per 1,000 mm 0.04 in per 39.4 in

Decarburisation

The maximum permissible decarburisation depth:

Outer surface ≤ 0.30 mm (0.012 in) Inner surface ≤ 0.20 mm (0.008 in)

How to Order

To ensure fast and accurate delivery of rock drill steel, we recommend that your order contains the following information:

1
Quantity
2
Grade
3
Denomination
4
Hole Size

※ Any special requirements regarding tolerances, lengths, maximum bundle weight, or corrosion protection should also be stated in your order.

Get In Touch

Ready to Place Your Order?

Our team is ready to help you find the right drill steel solution for your project. Contact us today for a fast, accurate quote.

Send Us an Enquiry [email protected]