Plain-Type Liner Bushing Dimensions (Type L)
Plain-type liner bushings (Type L) are precision-engineered components designed for permanent installation in jigs to receive renewable bushings. These bushings, often referred to as master bushings, are essential for accurate alignment and durability in drilling or reaming applications.
All dimensions conform to ASME B94.33 standards for inch-series bushings, ensuring compatibility and reliable interchangeability.
Overview — Plain-Type Liner Bushings (Type L)
Type L plain-type liner bushings are permanent master bushings used to locate and support renewable drill bushings in jigs and fixtures. Specified to ASME B94.33 (inch series), these bushings provide precise alignment, interchangeability, and wear resistance for high-volume drilling, reaming, and boring operations.
- Standardized sizing: Inside diameter A, body diameter B, body length C, and minimum radius D.
- Tight concentricity: A-to-B concentricity held within 0.0005 T.I.R. on finish-ground parts.
- Ideal for renewable systems: Serves as the permanent seat for slip or fixed renewable bushings.
- Inch-series coverage: Ranges matched to common fractional, wire, and letter drill sizes.
Selection Guidelines
- Choose Inside Diameter A based on the renewable bushing’s hole size range your process requires.
- Confirm Body Diameter B to match the jig bore; maintain recommended press fits for stability.
- Set Body Length C to ensure adequate support and seating area in the fixture.
- Check Radius D to reduce stress concentrations and improve seating at the base of the bushing.
Tip: For quick conversions, see Decimal equivalents of fractional, wire and letter sizes.
Typical Applications
Type L liner bushings are widely used in aerospace, automotive, heavy equipment, and general manufacturing for fixtures that require repetitive accuracy. They enable fast replacement of worn renewable bushings while preserving the jig’s master geometry.
- Drilling and reaming stations on transfer lines
- Multi-spindle drill fixtures and plate jigs
- Precision boring and dowel pinning operations
Installation & Fit Notes
- Press fit: Use appropriate interference between jig bore and body diameter B; verify hardness and surface finish of the jig material.
- Alignment: Ensure jig bores are perpendicular to the work surface to maintain tool life and hole quality.
- Lubrication/cleanliness: Keep seating surfaces clean; lightly lubricate during assembly to avoid galling.
- Renewable pairing: Confirm compatibility with slip/fixed renewable bushings (e.g., Type SF) to your process needs.
FAQ — Type L Liner Bushings
What’s the difference between a liner bushing and a renewable bushing?
The liner bushing (Type L) is permanently pressed into the jig and provides the locating seat. The renewable bushing is replaceable and provides the working hole that guides the tool.
How do I select the correct body length C?
Pick the shortest length that provides full seating and support in your jig plate while maintaining adequate wall thickness around the bore.
Can Type L bushings be used with both slip and fixed renewables?
Yes. Type L liner bushings are intended to pair with slip or fixed renewable bushings, depending on whether you need quick changeover or maximum rigidity.
Are these sizes metric?
This page lists inch-series sizes to ASME B94.33. For metric applications, select metric-standard bushings specified to the appropriate ISO/DIN standards.
Notes: All dimensions are in inches. For finish-ground bushings, Diameter A should be concentric to Diameter B within 0.0005 T.I.R. for optimal performance.
Supplements
Reference
- ASME B94.33-1996, Jig Bushings (Inch Series)