The Foundation of Mold Alignment
Leader pins and guide bushings are the alignment system that ensures your mold halves close in the correct position every single cycle. Misalignment of even a few thousandths of an inch causes flash, parting line damage, accelerated wear, and ultimately, rejected parts.
Tooling Components supplies precision-ground leader pins and guide bushings manufactured to tight tolerances from premium tool steel and bronze. We stock both inch and metric sizes from leading manufacturers, and we can source custom configurations based on your drawings.
Product Range
| Component | Material | Hardness | Available Sizes | Applications |
|---|---|---|---|---|
| Straight Leader Pins | H13 / SUJ2 Tool Steel | 58-62 HRC | 12mm-60mm dia, up to 300mm length | Standard injection molds, press-fit installation |
| Shouldered Leader Pins | H13 Tool Steel | 58-62 HRC | 16mm-50mm dia, up to 250mm length | Molds requiring positive retention, heavy-duty alignment |
| Guide Bushings (Straight) | Bronze / Tool Steel | 50-55 HRC | Matching pin sizes, various wall thicknesses | Receiving component for leader pins in mold plate |
| Shoulder Bushings | Bronze / Tool Steel | 50-55 HRC | 16mm-50mm ID, flanged | Replaceable alignment bushings with shoulder retention |
| Ball Bearing Bushings | Bearing Steel + Ball Bearings | 60+ HRC | Standard metric sizes | High-cycle molds requiring friction-free alignment |
| Self-Lubricating Bushings | Bronze + Graphite | N/A | Standard sizes | Molds where lubrication access is limited |
Material Selection Guide
The right material pairing between leader pin and bushing is critical. Hard-on-hard pairings reduce galling; bronze-on-steel provides self-lubrication.
Common Pairings
- Steel Pin / Bronze Bushing: Most common for general molds. Bronze provides natural lubricity.
- Steel Pin / Steel Bushing: For high-load applications. Requires proper lubrication.
- Steel Pin / Ball Bearing Bushing: High-cycle molds (100K+ cycles) needing minimal friction.
- Steel Pin / Graphite-Impregnated Bushing: For molds where liquid lubricant is impractical.
Sizing & Tolerances
Proper clearance between leader pin and bushing is essential for smooth operation. Too tight: the mold binds. Too loose: the mold shifts.
Standard Clearances
- General-purpose molds: H7/h6 fit (0.005-0.015mm clearance)
- Precision molds: H6/h5 fit (0.003-0.008mm clearance)
- Large molds: H8/h7 fit (0.010-0.030mm clearance)
- Pins: Ground to h6 tolerance as standard
- Bushings: Bored to H7 tolerance as standard
- Surface finish: Ra 0.4 microns or better on sliding surfaces
Industries Served
Injection Molding
Standard and precision alignment for thermoplastic and thermoset molds
Metal Stamping
Heavy-duty leader pins and bushings for die sets and press tools
Die Casting
High-temperature alignment components for aluminum and zinc die casting
Compression Molding
Alignment systems for rubber, composite, and thermoset compression molds
Why Tooling Components?
38+ Years Experience
Family-owned since 1987. Deep knowledge of mold alignment systems.
Same-Day Quotes
Send your drawings or BOM and get a response the same day.
BOM Kitting Available
We kit your order per BOM and label parts by PO or job number.
Call us at 814-438-7657 or schedule a meeting below.