ENGINEERING METROLOGY • BEND TOLERANCE STANDARDS

Aerospace Sheet Metal Bend Allowances, K-Factors & Tolerances

Empirical bend deductions calibrated to our TRUMPF precision tooling. Design rules for bend radii, grain orientation, and minimum flange heights for aerospace aluminum alloys and defense-grade stainless steel.

Angular Tolerance ±0.25° – ±0.5° Dynamic Crowned

Flange Length ±0.005" Formed Feature Tolerance

K-Factor Calibration EMPIRICAL Tool-Matched Constants

Grain Direction CROSS-GRAIN Crack Prevention Rules

Fast-Track CAD Intake → View Machine Specifications Direct: (860) 410-1801

MATHEMATICAL SHEET METAL MECHANICS

Bend Formulas & Empirical K-Factor Guide

When sheet metal is bent, the outer fibers stretch in tension while the inner fibers compress. The neutral axis shifts inward. Fabtron calibrates exact K-factor and Bend Deduction ($BD$) values into our CAD/CAM software to guarantee that flat blank laser cuts fold into exact print dimensions.

Primary Sheet Metal Bend Formulas:

Bend Allowance (BA):

BA = π/180 × θ × (R + K × T)

Outside Setback (OSSB):

OSSB = tan(θ/2) × (R + T)

Bend Deduction (BD):

BD = 2 × OSSB − BA

TECHNICAL SPECIFICATIONS & COMPLIANCE

Frequently Asked Engineering Questions

Detailed answers regarding our Plainville facility capabilities, material certifications, testing protocols, and defense contract compliance.

Q: Why does 6061-T6 crack during tight radius bends?

6061-T6 is artificially aged to high yield strength, giving it low elongation compared to 5052-H32. If bent parallel to the rolling grain with an inside radius less than 2x thickness, the outer bend fibers will crack. Fabtron nests parts across sheet grain to ensure defect-free forming.

DIRECT EXECUTIVE ENGINEERING CONSULTATION

Ready to Discuss Your Fabrication Requirements?

Speak directly with Garret Maino and our Plainville manufacturing engineering staff. Upload drawings for immediate DFM analysis and quotation.

Submit CAD Drawings → Call Plant: (860) 410-1801