I. Product Overview

This step hollow connecting sleeve is made by CNC lathe integrated turning, with an external one-piece locating boss and an internal stepped through-hole processed simultaneously. The external steps control the insertion depth, while the internal stepped holes are compatible with different outer diameter shaft parts, achieving precise positioning and guiding transition; the steel can be heat treated to enhance hardness and wear resistance, suitable for frequent disassembly and assembly conditions.
Supports carbon steel, stainless steel, aluminum alloy, brass and other materials; outer diameter, length, and inner/outer step sizes can be customized according to customer drawings or physical samples; capable of handling small batch trials and long-term bulk supply; finished products are inspected and controlled for appearance and dimensions.

II. Core Highlights of Craftsmanship

1. Integrated CNC turning and forming, excellent coaxiality
   The cylinder, end positioning steps, and internal stepped holes are all machined in one operation, with no splicing or welding. The concentricity of the inner and outer circles is high, and the shaft insertion and sliding are smooth without jamming.
2. Double-sided stepped structure, strong positioning adaptability
   The outer rib provides axial limitation, the internal stepped holes can match two specifications of shaft bodies, a set of sleeves completes the transition and positioning, simplifying the number of equipment parts.
3. End face is smooth and even, assembly fits without gaps.
   End faces are precision turned smooth, assembled with tight fit, evenly distributed stress, and are less prone to position displacement over long-term use.
4. Full-area deburring treatment, protecting mating parts
   All internal and external hole openings, step corners are deburred and smoothed, ensuring the insertion and removal process will not scratch the shaft or seals and other components.

Section 3: Optional Customized Raw Materials

1. 45# Carbon Steel (Recommended)
   Supports quenching and tempering, high hardness and good wear resistance, first choice for tooling and mold locating sleeves.
2. 304 Stainless Steel
   Corrosion and rust resistance, suitable for working environments with moisture and slight corrosive media.
3. 6061 Aluminum Alloy
   Lightweight, lightweight instruments, non-high-load positioning components.
4. H62 Brass
   Excellent self-lubricating performance, suitable for low-load frequent sliding scenarios, and can meet electrical conductivity requirements.

4. Optional Surface Treatment Processes

• Quenching Blackening: Enhances hardness, wear resistance and anti-corrosion, mainstream solution for mechanical bushes
• Nickel Plating: Rust and oxidation resistance, internal components for precision instruments
• Galvanized: Economical basic anti-rust, suitable for indoor general mechanical accessories
• Original Color Precision Turning and Polishing: High Precision Precision Assembly Conditions

Five, Applicable Application Scenarios

✅ Non-standard automated production line step positioning bushing
✅ Various mold fixture shaft connecting bushes
Sensor Module Component Limiting Sheath
✅ Inspection fixture, small fixture guide connecting parts
✅ Miniature machinery equipment step shaft positioning protective sleeve

Six, Core Product Advantages

1. Numerical control precision machining, internal and external step sizes, total length, and bore diameter can all be freely adjusted.
2. Integrated design of internal and external steps, simultaneously achieving positioning and multi-specification shaft connection
3. Supports heat treatment quenching hardening, effectively extending the service life of parts
4. A variety of materials and surface processes are available, suitable for different working conditions of abrasion resistance, rust prevention, and lightweightening.
5. Single piece sampling available, can produce complete sets of corresponding step shafts, ensuring mating accuracy.

Chapter 7: Common Procurement Q&A

Q1: Can the internal step hole size and external boss height be modified separately?
A: Yes, all step sizes and cylinder lengths can be independently customized according to the drawings.
Q2: What material and process are most suitable for long-term reciprocating sliding use?
A: 45# steel quenched and darkened treatment, with the best wear resistance.
Q3: Can it be made into a blind hole style with one end sealed?
Supports through-hole and single-sided blind hole structures for processing.
Q4: Can the corresponding stepped shaft be processed and shipped together?
A: Support synchronous processing of sleeve and matching shaft parts, strictly control assembly gap.