For rotary cutting rule to perform during the diemaking and diecutting processes,the back notching must be accurate, burr free, and specific to the appplication. Most curved rule for 50” and 66” rotary diecutters is made with a back notch that is 1/2” (12.7 mm) deep on 1/2” (12.7 mm) centers for an accurate method of determining bridge placement.

When bending a circle for a rotary diecutter, you can improve the seating of the rule by specifying a closer notch, such as N2. When ordering curved rule for cylinders under 9” (228 mm), you can improve the seating of the rule by specifying close notching. We can alter the depth of the notching to suit your application.

Proper rule seating is critical to prevent premature rule failure. Accurate back notching along with National’s Accu Curve system are two of the best ways to assure the rule seats properly on the cylinder.

1/2” (12.70 mm) Centers
Standard depth – 1/2” (12.70 mm).
Other depths available on special request.

.312” (7.92 mm) Centers
Standard depths – either 21/32” (16.67 mm) or 1/2” (12.70 mm).
Other depths available on special request.

3/8” Centers (9.53 mm)
Standard depth – 1/2” (12.70 mm).
Other depths available on special request.

.265” (6.73 mm) Centers
Standard depth- 1/2” (12.70 mm).
Other depths available on special request.

.431” Centers (10.95 mm)
Standard depth -.525” (13.33 mm).
Other depths available on special request.

National offers the option of curved rule with no back notch. Available in diameters from 11” (280 mm), no notch curved rule works well in places where a solid rule will add strength.

  indicates a Zimmer Industries innovation.

Curved rule with no back notch shown.

Accurate curving is necessary for rule to properly seat on the cylinder. Rule that is too loose or too tight may flex and fail prematurely. Our exclusive AccuCurve system insures the rule will properly fit the cylinder. By thermally transforming the structure of the steel from a straight to a curved state, we can eliminate the memory in the steel that causes the rule to pull away from the cylinder.

Reverse curving is available on all products for use in rotary rule processors that require this style.