Mandrel
The mandrel's profile determines the ring's internal shape, which is how contoured near-net rings are produced instead of plain rectangles.
A mandrel is a cylindrical tool inserted through a hollow workpiece to support and shape its bore. In ring rolling, the mandrel presses against the ring's inside while a driven roll presses the outside, thinning the wall and growing the diameter.
- Definition
- Internal tool supporting the bore
- Used in
- Ring rolling, hollow forging
- Controls
- Bore dimension and internal profile
- Profiled versions
- Produce near-net internal sections
Mandrel at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Definition: Internal tool supporting the bore
- Used in: Ring rolling, hollow forging
- Controls: Bore dimension and internal profile
- Profiled versions: Produce near-net internal sections
How It Shapes a Ring
The ring is squeezed between the driven outer roll and the mandrel. Wall thickness reduces, and since volume is conserved, the diameter grows. The mandrel controls the bore dimension throughout.
Profiled Mandrels
A profiled mandrel rolls a contoured internal section — a bearing race groove pre-form, for example — reducing the machining stock that would otherwise be turned away. That saves both material and machining time.
Topics covered on this page
- mandrel forging
- ring rolling mandrel
- what is a mandrel
- hollow forging mandrel
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What is a mandrel used for in forging?
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Supporting and shaping the bore of a hollow workpiece, particularly in ring rolling where it presses against the ring's inside face.
What does a profiled mandrel do?
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It rolls a contoured internal profile into the ring, reducing subsequent machining.
Is a mandrel used in open die forging?
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Yes, for expanding and shaping hollow forgings such as sleeves and bushes.