Internally Threaded Taper Pin, Types A and B

Internally Threaded Taper Pin — Product Introduction

The internally threaded taper pin is a tapered locating fastener conforming to GB/T 118-2000, with a taper of 1:50 and an internally threaded hole on the large-end face, so that a pin extractor or bolt can be screwed in to pull the pin out during disassembly. The product is available in Type A (ground, taper surface roughness Ra = 0.8 μm) and Type B (machined or cold-formed, Ra = 3.2 μm), with nominal diameters from 6 mm to 50 mm and nominal lengths from 16 mm to 200 mm (above 200 mm in increments of 20 mm), and a tolerance class of h10.

I. Product Features

• Precision difference between Type A and Type B: Type A is ground, with a taper surface roughness of Ra = 0.8 μm for higher precision. Type B is machined or cold-formed, with a taper surface Ra = 3.2 μm, suitable for general-precision applications.
• 1:50 taper self-locking: The very small taper relies on interference fit with a reamed taper hole, achieves self-locking under transverse loads, provides high positioning accuracy, and allows repeated assembly and disassembly without affecting positioning accuracy.
• Internally threaded extraction structure: The large-end face has an internally threaded hole (M4 to M24), specifically for blind holes or difficult extraction situations, so that the pin can be removed by screwing in a pin extractor.
• Variety of materials and hardness: Common materials include free-cutting steel (Y12, Y15), carbon steel (35, 45), alloy steel (30CrMnSiA), and stainless steel (1Cr13, 2Cr13). Steel 35 has a heat-treated hardness of 28-38 HRC, steel 45 of 38-41 HRC, and alloy steel of 35-41 HRC.
• Optional surface treatment: Can be supplied untreated, black oxide, phosphated, or zinc plated with passivation.

II. Product Advantages

• Dedicated to blind holes: Designed specifically for non-through blind holes. The internal thread structure solves the difficulty of removing a taper pin from a blind hole, so no knocking out from the other end of the hole is needed during maintenance.
• High positioning accuracy: The taper fit eliminates clearance, ensuring accuracy over long-term repeated assembly of components, with strong resistance to vibration displacement.
• Convenient disassembly: The internal thread at the large end works with a pin extraction tool for easy removal, avoiding damage to the hole wall, and is suitable for applications requiring frequent disassembly.
• Complete specification system: Nominal diameters from 6 mm to 50 mm and lengths from 16 mm to 200 mm meet different positioning needs, from small precision tooling to heavy mechanical equipment.

III. Application Scope

• Mechanical manufacturing and assembly: Positions requiring precise centering and alignment in molds, fixtures, machine tools, and reducers.
• Blind hole positioning connections: Positioning and fixing in non-through pin holes or closed cavities, the core application scenario of internally threaded taper pins.
• Frequent disassembly applications: Equipment requiring frequent disassembly and maintenance, such as precision mechanical assemblies connecting missile bodies to their main structures.
• General industry: Pin connections requiring high-precision positioning and easy disassembly in various mechanical equipment.