DIN 6935 Sheet Metal Bend Allowance & K-Factor Standard 1:1 DXF · SVG · PDF Default Spec: 200 × 140 × 45 mm (T=1.5mm)

Sheet Metal 4-Flange Pan & Electrical Enclosure Flat Pattern Unfolder (K-Factor DXF)

1:1 CAD ENGINE READY

Sheet Metal 4-Flange Pan & Electrical Enclosure Flat Pattern Unfolder (K-Factor DXF)

1CAD Style & Material SetupSheet

Select CAD Style / Model (36)Search & Filter

Material Stock Preset (Auto-Sets Caliper T & Kerf K)

Display Units

Reference Mode

2Dimensions (ID Mode)Millimeters (mm)

Internal Length (L)200 mm

Internal Width (W)140 mm

Internal Height / Flange (H)45 mm

Inside ID: 200×140×45mmOutside OD: 203×143×48mm

Thickness (T mm)

Laser Kerf (K mm)

3Brand Logo & 1:1 ExportZero Login

2D & 3D Brand Logo Mockup:

📤 Upload Logo

Print Artwork Bleed Guide:

Embed Spec Sheet & 50mm / 1" Scale Bars (Added on separate DIMENSIONS layer)

Pre-Flight Geometry Audit8/8 PASSED

PASS
Closed Outer Contours: 1 closed LWPOLYLINE cut loop(s) verified
PASS
Zero Duplicate Cut Paths: 20 unique segments (0 laser double-burns)
PASS
Flute & Kerf Tolerance Guard: T=1.50mm, K=0.000mm within structural limits
PASS
ISO Layer Color Separation: CUT (Red), CREASE (Blue), SCORE (Emerald), DIMENSIONS isolated
PASS
1:1 Physical Unit Header: Explicit mm/in SVG viewBox + DXF $INSUNITS=4 + 50mm PDF bar
PASS
Exact 2D Cut Bounding Parity: Cut Bounds 287.35×227.35mm === Blank Size
PASS
2D ↔ 3D Kinematic Model Sync: Archetype 'sheet_metal_pan' synced (2 3D component(s))
PASS
True Vector Sheet Nesting Sync: 1:1 vector paths mapped to multi-up sheet grid

100%

CUT (1.01m) CREASE/SCORE (0.68m)● 1 Loops · Est. Cut: ~33s

1:1 Synced · Blank: 287.35 × 227.35 mm

2D 1:1 Unfolded Vector BlueprintBlank: 287.35 × 227.35 mm (11.31" × 8.95")

3D Interactive Fold & Orbit (Kraft Board)

80%

0%100%

Camera:

Yaw: -28°Pitch: 24°

⟳ Drag Anywhere to Rotate 3DL=200 × W=140 × H=45mm

BASE (200×140mm)4 Corner Reliefs (K=0.42)

FRONT (H=45)

REAR WALL

Flat Pattern Size

287.3 × 227.3 mm

90° Bend Allowance

3.35 mm

Bend Deduction (BD)

2.65 mm

K-Factor Standard

K = 0.42 (DIN 6935)

Structural & Manufacturing Specification Summary

Quick Default Download: ↓ .DXF ↓ .SVG ↓ .PDF

When bending a 4-flange sheet metal pan or electronics chassis on a CNC press brake, the outer fibers stretch while the inner fibers compress along a neutral axis governed by the material's K-Factor (typically K = 0.42 for mild steel and aluminum in air bending). If you do not subtract the Bend Deduction (BD) from each flange or omit corner bend relief notches, the metal tears at the corners and finishes oversized. Our parametric unfolder calculates exact DIN 6935 90-degree bend allowances and places square corner relief cutouts for fiber laser, plasma, or waterjet cutting.

CUT LAYER #EF4444 (ACI 1)

CREASE / BEND #2563EB (ACI 5)

SCALE HEADER $INSUNITS=4 (1:1 mm)

SIMULATION 2D + 3D + Nesting

Pre-Calibrated Industry Sizes (2)

Standard Product Presets Built on This Sheet Metal 4-Flange Pan Engine

220 × 140 × 40 mm (T=1.5mm)

1.5mm Sheet Metal Chassis Tray

220 mm x 140 mm Base with 40 mm Vertical 90-Degree Press-Brake Flanges

Load Preset Spec →

430 × 200 × 44 mm (T=1.5mm)

1U Rackmount Electronics Chassis Pan

EIA-310 19-Inch Rack Inner Chassis Width (430 mm) × 200 mm Depth × 44.0 mm (1U) Height

Load Preset Spec →

Structural Geometry & Allowances

Mathematical Blank & Tolerance Formulas

90-Degree Bend Allowance (BA)

BA = (pi / 2) * (R_inside + K_factor * T)

Computes the arc length of the neutral sheet metal axis across a 90-degree press-brake bend.

Bend Deduction (BD)

BD = 2 * (R_inside + T) - BA

Total amount subtracted from the sum of outer flange lengths to determine the true flat pattern blank size.

Corner Bend Relief Notch (R_relief)

R_relief = max(2.0 mm, 1.5 * T)

Prevents adjacent 90-degree flanges from colliding and tearing at the bend intersection.

Pre-Press & Production SOP

Step-by-Step Export & Assembly Guide

1 Enter the finished Base Length (L), Base Width (W), Vertical Flange Height (H), and Sheet Metal Thickness (T, e.g., 1.5mm for 16ga steel).
2 Inspect the unfolded flat blank with automatic corner bend relief notches and press-brake bend lines (BLUE dashed layer).
3 Export as 1:1 .DXF (uncheck 'Include Dimensions Layer' for direct fiber laser or plasma CAM import) or .PDF for the press-brake operator sheet.
4 Fold the 4 flanges upward to 90 degrees on a box-and-pan brake or CNC press brake, then TIG/MIG tack-weld the four vertical corner seams.

Board Caliper, Laser & Die-Cutting Reference

Material Thickness, Creasing Matrix & Laser Kerf Settings

Material / Sheet Stock	Caliper Thickness (T)	Recommended Tooling / Laser Setup	Allowance / Kerf Spec	Primary Use Case
16 Gauge Cold Rolled Mild Steel (CRS)	1.52 mm (0.060 in)	Fiber Laser / Plasma + 12mm V-Die Press Brake	K-Factor: 0.42 / Inside R: 1.5mm	Electrical junction boxes, industrial control panels, shop trays
5052-H32 Aluminum Sheet	2.00 mm (0.080 in)	Fiber Laser / Waterjet + 16mm V-Die	K-Factor: 0.40 / Inside R: 2.0mm	Audio amplifier chassis, drone brackets, marine enclosures
304 Stainless Steel (18 Gauge)	1.20 mm (0.048 in)	Nitrogen Fiber Laser + 10mm V-Die	K-Factor: 0.44 / Inside R: 1.5mm	Commercial kitchen drip pans, medical trays, food-grade hoppers

Packaging & CNC Engineering FAQ

Frequently Asked Questions — Sheet Metal 4-Flange Pan

Why are corner relief notches mandatory on a 4-flange sheet metal box?

Where two perpendicular 90-degree bend lines meet at a corner, the metal inside the bend radius would overlap and pinch if cut straight to the intersection. A relief notch of at least 1.5x sheet thickness gives both flanges clean clearance to fold up without tearing or deforming the corner.

What K-Factor does this sheet metal generator use?

Our calculator uses the industry standard K = 0.42 for 90-degree air bending on a V-die with an inside bend radius equal to material thickness (R = T), compliant with DIN 6935.

Are the bend lines on a separate layer in the exported DXF file?

Yes! The outer cut profile with corner reliefs is placed on the 'CUT' layer (ACI Color 1 Red), while the 4 press-brake bend lines are isolated on the 'CREASE' layer (ACI Color 5 Blue) so your laser cutter does not cut through the bend lines.