Intermediate Roll for Tension Levellers in GCr15 and 9Cr2Mo
The intermediate roll sits between the work rolls and the back up rolls and carries the bending load across to the support side. Material choice decides how long it holds profile: GCr15 is the cost effective wear resistant option for small and medium diameters, 9Cr2Mo is the higher strength choice for heavier duty.
- GCr15 tempering HB 270-300
- Induction hardened surface HRC 61-63
- Hardened layer depth 3-4 mm
- Optional hard chrome plating 0.05-0.08 mm
Key Benefits
Why the intermediate roll specification matters.
Bridges Work Rolls And Back Up Rolls
As the transmission and support component in the roll system, it carries load from small diameter work rolls into the back up rolls without deflecting.
Surface Finish That Protects The Work Roll
Surface roughness Ra 0.2-0.4 micron keeps contact smooth so the work roll surface is not damaged from behind.
Material Matched To Duty
GCr15 for small to medium diameter cold rolling duty, 9Cr2Mo chromium molybdenum alloy steel where strength requirements are higher.
Where It Is Used
Lines that use these rolls.
- Cold rolled strip tension levelling lines for stretching and bending straightening
- Galvanizing and aluzinc coating lines
- Colour coating line finishing sections
- Non ferrous strip levelling lines
Who It Is For
- Levelling line maintenance teams holding roll stock
- Coating line operators replacing cassette internals
- Equipment builders sourcing complete roll systems
- Buyers matching an existing roll by material and hardness
Problems It Solves
- Intermediate roll wear changing the roll gap geometry
- Work roll damage caused by a rough support surface
- Roll deflection under bending load on wide strip
- Sourcing a replacement when only the old roll is available
Technical Features
Two materials, documented properties.
GCr15 Bearing Steel
High carbon chromium bearing steel with good wear resistance, tempering HB 270-300 and induction hardened surface HRC 61-63 with a 3-4 mm hardened layer.
9Cr2Mo Alloy Steel
Chromium molybdenum alloy steel used where higher strength is required than GCr15 provides.
Optional Chrome Plating
Hard chrome plating of 0.05-0.08 mm can be added, with surface roughness held at Ra 0.2-0.4 micron.
Specifications
Diameter and barrel length are made to your cassette drawing. Reference installations include rolls of 40 mm diameter by 2076 mm.
| Materials | GCr15 bearing steel or 9Cr2Mo chromium molybdenum alloy steel |
|---|---|
| Tempering | HB 270-300 for GCr15 |
| Surface Hardness After Induction Hardening | HRC 61-63 |
| Hardened Layer Depth | 3-4 mm |
| Optional Hard Chrome Plating | 0.05-0.08 mm |
| Surface Roughness | Ra 0.2-0.4 micron |
| Reference Size | 40 mm diameter by 2076 mm barrel, surface hardness HRC 60-62 |
| Non Standard Sizes | Supported against drawing |
Materials
- GCr15 high carbon chromium bearing steel
- 9Cr2Mo chromium molybdenum alloy steel
- Optional hard chrome plated surface
Manufacturing Process
Material Selection
Roll diameter, line type and load decide between GCr15 and 9Cr2Mo.
Rough Machining
Bar is turned close to size and stress relieved before hardening.
Induction Hardening
The surface is hardened to HRC 61-63 with a 3-4 mm case.
Grinding And Plating
The barrel is ground to Ra 0.2-0.4 micron, with optional chrome plating at 0.05-0.08 mm.
Quality Control
- Material certificate for GCr15 or 9Cr2Mo
- Hardness test after induction hardening
- Hardened layer depth verification
- Roughness and runout measurement before packing
Customization Options
- Non standard diameters and lengths against drawing
- Material chosen for the duty rather than a single default
- Chrome plating added or omitted
- Matched sets supplied per cassette
Use Guide
- Replace intermediate rolls as a set so support is even across the width
- Check roll surface when work rolls show repeat marks
- Keep spare rolls protected against corrosion, bearing steel rusts quickly
- Confirm hardness requirement when ordering against an old sample
How It Compares
Choosing the material.
| GCr15 | Cost effective wear resistance, ideal for small to medium diameter cold rolling rolls. |
|---|---|
| 9Cr2Mo | Chromium molybdenum alloy steel for higher strength duty where GCr15 would be working at its limit. |
| Unhardened support rolls | An induction hardened HRC 61-63 surface holds profile far longer under continuous levelling load. |
Related Products
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Intermediate Roll in GCr15 and 9Cr2Mo FAQ
Which material should we choose?
GCr15 is the cost effective option for small and medium diameter cold rolling rolls. 9Cr2Mo is used where higher strength is needed. Tell us diameter, line type and load and we recommend one.
What hardness do the rolls reach?
Surface hardness after induction hardening is HRC 61-63 with a hardened layer 3-4 mm deep. GCr15 is tempered to HB 270-300 before hardening.
Is chrome plating available?
Yes, optional hard chrome plating at 0.05-0.08 mm thickness, with surface roughness held at Ra 0.2-0.4 micron.
Can you make non standard sizes?
Yes. Non standard customization is supported, we work from your drawing or a measured sample.
Do you have reference sizes?
Rolls of 40 mm diameter by 2076 mm with surface hardness HRC 60-62 have been supplied for galvanizing line service.
What do you need to quote?
Roll drawing or sample dimensions, line type, strip width and material, and quantity per set.
Match Your Intermediate Rolls
Send the roll drawing or dimensions with your line data and we confirm material, hardness and price.