Metal Assessment - Fastening Components and Principles Lecture

Hook and Loop

• Velcro is a brand name

• many formats and sizes

  • sew on

  • adhesive backed (pressure sensitive) not permanent

  • 50/50

  • coins (circles of velcro)

  • loop tape (C-fold)

Screws, Nuts, Buckles, Hooks

• Chicago screw

• Wing nut

• parachute buckle

• UEP buckles

• hook/eye

BOA and Click

• allows for user adjustment easily

Snaps

Use hand press to press stud to eyelet or socket to cap.

Rivet Materials and Varieties

Rapid/Speedy or Compression

• aluminum

• steel

• stainless steel

• brass

• nickel-plated copper

• copper

Rivet Anatomy

• cap/head

  • single cap or double cap

• stem/post/shank

  • indent allows click into place

• burr

General Principles

• number

• location

  • 3 point forces

  • leverage

• independence

  • velcro vs snap

  • accessibility

  • is independence goal?

• adjustability

• replace and repair

Rivet Size

Diameter

• > thickest piece (T)

• < 3x thinnest piece (t)

Length

• total thickness

• better to err long

• don’t want to drive shank into head

Edge Spacing

• important for strength

• center of drilled hole to end > 2x rivet diameter

Rivet Spacing

• minimum - 3x rivet diameter

• maximum - 2-4x material thickness (T)

Setting a Rivet

• dome first head (optional)

• pass shank through materials

• compress - ensure head is in contact with surface

• set burr

• remove excess length leaving enough to create second head

Finishing

Create second head -

• flatten cut end to fill hole

• dome/remove rough edges

• confirm rivet is secure/tactile check

Rivet Removal

reasons to remove:

• too short, misaligned, head(s) rough, broken, loose/wrong size or material, growth. etc.

1. remove head or cap

- screwdrive, chisel, cutting pliers, router

2. pin punch

- select correct size

3. hard impact

- hammer