Oct 7, 2026
Metal Spacers for Slitter Arbors: Tolerance Stacking and Set Planning
Metal spacers position slitter knives on the arbor. Learn tolerance classes, how spacer stacks define slit width, and planning spare sets for fast changeovers.
Every slit width on a slitting line exists because someone stacked the right metal spacers between the knives. Get the spacer stack right and the knives run true; get it wrong and the whole width plan drifts.
What Spacers Do
Spacers are precision-ground steel discs that fix the position of each top and bottom knife on the arbor. Their thicknesses add up to the target slit width, so their individual thickness tolerance multiplies across the stack.
Tolerance Classes
Spacers are commonly supplied in ground and lapped grades:
• Ground spacers — thickness tolerance around ±0.005 mm, suitable for most steel strip work
• Lapped spacers — tolerance down to ±0.002 mm for foil, shims and precision electrical steel
• Rubber bonded spacers — combine spacing with stripping function on lighter lines
A practical article to pair with this one is circular metal slitter blades, which covers the knives these spacers position.
Planning Spacer Sets
Service centers build a spacer inventory around their most-run width programs. A useful rule: stock spacers in 5 mm steps from 10 mm upward, plus a fine set in 0.05 mm steps for width corrections. Label and store stacks per job so changeovers become a swap instead of a rebuild.
Bore fit matters as much as thickness — a sloppy bore lets the spacer run eccentric and the slit width wanders with it.
Why Choose zhongjian
zhongjian (ZHONGJIAN TECH) supplies metal spacers, rubber bonded rings and slitter knives with matched tolerances, so the whole stack runs as one system rather than parts from three vendors.
Send your width program and arbor details to contact zhongjian tech for a spacer set proposal with quotation.
