Sheet 08 of 15

Hems: Fold an Edge Back on Itself

In 4 minutes you'll fold the top edge of a bracket back on itself with a hem, and see how the hem's gap changes the flat length.

Part
Hems
Rule
Steel 2mm
Sheet
t 2 · R 2 · K 0.4
Time
4 min
Status
Open
  1. OP 10Watch
  2. OP 20Turn the part
  3. OP 30Build
  4. OP 40Inspect
  5. OP 50Quiz

OP 10Watch

Video in productionBuild along with the steps in OP 30 meanwhile.

OP 20Turn the part

The finished part

Drag to turn, scroll or pinch to zoom. Flat shows the blank before it is bent: the same sheet, the same frame.

OP 30Build it in SolidCraft

3D VIEWPART A OF 8 · mm
FRONT VIEWPART A OF 8 · mm12032
TOP VIEWPART A OF 8 · mm12062
RIGHT VIEWPART A OF 8 · mm6232
UP 90° R2 · FLANGE 30DOWN 180° R0.01
NOTESPART A OF 8 · mm1. ALL SIZES IN mm, TO THE OUTSIDE OF THE SHEET.2. SHEET 2 mm, INSIDE BEND RADIUS 2 mm, K-FACTOR 0.4:THE SHEET METAL RULE “Steel 2mm”.3. THE FLAT SIZE IS YOURS TO FIND.TITLEHEMSSHEET08PARTA OF 8MATERIALSTEEL 2MMTHICKNESS2 mmUNITSmmOPEN CAD ACADEMYSHEET METAL WITH SOLIDCRAFTPROJECTION
Build your part from this drawing: all sizes in mm, to the outside of the sheet.
The finished part
Rule
Steel 2mm
Thickness
2 mm
Bend radius
2 mm
K-factor
0.4

As typed in this exercise

  • Sketch Base on XY: rectangle (0, 0) to (120, 60)
  • Flange: height 30
  • Hem: length 10

Your task

Build this bracket from the drawing above.

  1. The rule from the drawing's notes (leave its Hem Gap as it is), the base, and the wall on the long front edge.
  2. New this time: Hem on the top edge of the wall: Length from the drawing, Gap empty.
  3. Flat Pattern: read the flat length across the bends and the Bends.
  4. Edit the hem, Gap 2 mm, and read the flat length again.

What to write down

  • Box 1: The flat length across the bends with the rule's gap (the Flat size row of the Flat Pattern; the other side is 120 mm).
  • Box 2: The same length with Gap 2 mm.
  • Box 3: The number of bends (the Bends row).

Type them below and press Check. If your hem folds to the other side of the wall, the numbers are the same: Flip only changes the side.

OP 40Inspect

Enter what SolidCraft shows you. Each value is checked against SolidCraft's own result, within the tolerance shown. Nothing you type leaves this page.

± 0.05 mm mm

± 0.05 mm mm

exact

Stuck? Compare with the finished part
Download the finished part

Open it in SolidCraft (File › Open) next to yours and compare the timeline, the rule and each feature's sizes: the first one that differs is where yours went wrong.

exercise · Steel 2mm · t 2 · R 2 · K 0.4 · all dimensions in mm, from the blank's left and bottom edges
0120012096.9338.739.26096.93012096.93UP 90° R2DOWN 180° R0.01

Flat blank 120.000 × 96.933 mm · 2 bends

BendAngleDir.R mmLength mmAllowance mm
190°up21204.398
2180°down0.011202.545
exercise-gap2 · Steel 2mm · t 2 · R 2 · K 0.4 · all dimensions in mm, from the blank's left and bottom edges
01200120101.194310.40101.190120101.19UP 90° R2DOWN 180° R2

Flat blank 120.000 × 101.195 mm · 2 bends

BendAngleDir.R mmLength mmAllowance mm
190°up21204.398
2180°down21208.796

OP 50Quiz

Q1How far does a hem bend the sheet?

Q2Where does the hem's Gap come from when you leave it empty?

Q3The hem folds to the wrong side. What do you do?