Dunham Tool manufactures a range of manual expanding mandrels (miser mandrel) with diameter capacities of 5/16" to 6". This expanding mandrel can be used with standard collets, vises, jaw chucks and many other special fixtures. These expanding mandrels are machinable by the customer. Multiple expanding mandrels are also used in other special fixtures for holding multiple workpieces 'side by side'.

1. Chuck the shank of the expanding mandrel in a collet, jaw chuck, or fixture.
2. With an Allen Key tighten the hex draw bolt until it expands .005.
3. Then machine the slotted member .001 larger than bore of part.
4. Loosen hex draw bolt, position part, tighten draw screw. The part is now chucked and ready for machining.

• Requires no special adapters
• Can be used with 5c collets or standard Jaw Chucks
• Can be used with vises or special fixtures
• Actuated manually via hex head draw bolt
• Available from 5/16” to 6” diameter
• Available from 1” to 2” expandable length
• Machinable by customer to desired diameter
• No draw back gives positive location