Complete Spring Making and Spring Steel Working: From Bar to Bounce
⟁ cover painted for this edition — the source module carried no illustrations
Complete Spring Making and Spring Steel Working: From Bar to Bounce
Springs store and release energy, powering mechanisms from mousetraps to vehicle suspensions. This campaign covers spring types, coiling, heat treatment, and applications.
Chapter 1: Spring Types
Type
Shape
Action
Use
Difficulty
Compression coil
Helical coil
Resists compression
Valves, suspensions, latches
Moderate
Extension coil
Helical coil with hooks
Resists extension
Gates, trampolines, tools
Moderate
Torsion coil
Helical coil with legs
Resists twisting
Clothespins, mousetraps, doors
Moderate
Leaf spring
Flat bar, curved
Resists bending
Vehicles, gates, traps
Low-moderate
Flat spring (clock)
Coiled flat strip
Stores energy
Clocks, music boxes
High
Volute spring
Conical coil
Resists compression (progressive)
Heavy machinery
High
Chapter 2: Spring Steel
Steel
Carbon %
Characteristics
Best For
Availability
1075
0.75%
Good spring properties, easy to work
General springs
Common
1084
0.84%
Excellent spring steel
Coil and leaf springs
Common
1095
0.95%
Very hard, good spring
Heavy-duty springs
Common
5160
0.60% + chromium
Excellent toughness, spring steel
Leaf springs, heavy coils
Automotive salvage
6150
0.50% + vanadium
Premium spring steel
Precision springs
Specialty
Salvage sources: 1) Vehicle leaf springs (5160 or similar): excellent for flat springs and large coil springs. 2) Garage door springs: high-quality spring steel wire. 3) Old bed springs: medium carbon spring steel. 4) Hay rake tines: spring steel wire. 5) Pallet banding: thin spring steel strip. 6) Old files (1095): can be annealed and re-forged into springs.
Chapter 3: Coil Spring Making
Compression spring: 1) Select spring steel wire (diameter determines spring strength). 2) Anneal wire (heat to cherry red, slow cool in ash). 3) Calculate mandrel size (mandrel diameter = desired coil inner diameter). 4) Wrap wire around mandrel (even spacing between coils). 5) Maintain consistent pitch (spacing between coils). 6) Cut to desired number of coils. 7) Grind ends flat (spring sits level). 8) Heat treat: heat to non-magnetic (cherry red), quench in oil. 9) Temper to blue (560°F) for spring properties. 10) Test: compress and release; spring should return to original length.
Wire Diameter
Mandrel Diameter
Spring Force
Application
1/16 inch
1/4-3/8 inch
Light
Small latches, pens
3/32 inch
3/8-1/2 inch
Light-medium
Mechanisms, tools
1/8 inch
1/2-3/4 inch
Medium
Latches, gates
3/16 inch
3/4-1 inch
Medium-heavy
Machinery, traps
1/4 inch
1-1.5 inch
Heavy
Vehicles, heavy machinery
Chapter 4: Leaf Spring Making
Leaf spring forging: 1) Start with flat spring steel bar (5160 or 1084). 2) Typical size: 1/4 x 2 inches, 18-36 inches long. 3) Heat entire bar evenly to cherry red. 4) Bend to desired curve (arc). 5) For multi-leaf: forge several bars of decreasing length. 6) Stack bars with longest on bottom. 7) Clamp together with center bolt. 8) Heat treat: harden (quench in oil), temper to blue. 9) Multi-leaf spring: each leaf adds to total spring rate.
Application
Bar Size
Length
Curve
Leaves
Trap spring
1/8 x 1 inch
8-12 inches
Moderate
1
Gate spring
1/4 x 1.5 inch
12-18 inches
Slight
1
Cart/wagon
1/4 x 2 inch
30-42 inches
Moderate
3-5
Vehicle (light)
1/4 x 2.5 inch
36-48 inches
Moderate
4-7
Chapter 5: Spring Applications
Application
Spring Type
Size
Function
Door closer
Torsion coil
Medium
Returns door to closed position
Gate latch
Compression coil
Small
Holds latch in locked position
Animal trap
Leaf spring
Medium
Powers jaw closure
Crossbow
Leaf spring (prod)
Large
Stores energy for bolt
Clock/mechanism
Flat coil
Small
Stores energy, powers movement
Vehicle suspension
Leaf spring (multi)
Large
Absorbs road shock
Mousetrap
Torsion coil
Small
Powers snap bar
Reference Card
Temper to blue for springs (springs must be tough, not hard; a blue temper (560°F) gives the right balance of hardness and flexibility; too hard and the spring shatters, too soft and it bends permanently). 2. Spring steel must return to shape (a properly heat-treated spring deforms under load and returns to its original shape when the load is removed; if it takes a permanent set, it needs re-tempering at a lower temperature). 3. Oil quench for spring steel (spring steels are medium to high carbon and should be quenched in oil; water quenching is too aggressive and causes cracking). 4. Consistent coil spacing matters (uneven spacing in a coil spring causes uneven force distribution; coils that are too close together bind; coils that are too far apart reduce spring rate). 5. Vehicle leaf springs are free spring steel (salvaged leaf springs from cars and trucks are excellent spring steel (usually 5160); they can be re-forged into any spring application). 6. Anneal before working (spring steel is too hard to bend or coil in its hardened state; annealing (heating and slow cooling) softens it for forming; heat treat after forming). 7. Grind coil spring ends flat (flat ends allow the spring to sit level and distribute force evenly; unground ends cause the spring to tilt and bind). 8. Springs are stored energy (a compressed or bent spring stores mechanical energy that can be released on demand; springs power clocks, traps, latches, and countless mechanisms).
