Project Snapshot

• Component: Linear motion shaft with custom end machining
• Size: Ø25 mm × 562 mm
• Material: 440C stainless steel
• Hardness requirement: HRC 52–54
• Mating bearing: SBR25UU (no support rail)
• Application: Machine-grade food equipment

This summary makes the key technical elements explicit. It allows engineers and buyers to quickly confirm whether this case matches their application, and anchors the discussion to measurable technical requirements rather than general capability claims.

Customer Requirements (Critical-to-Quality)

The customer stated that hardness and material selection were non-negotiable. In practical terms, this makes hardness, diameter control, surface finish, and straightness stop-ship items. A shaft can appear acceptable but still cause operational issues when paired with a bearing block.

Because the shaft operates without a support rail, alignment sensitivity increases. Local deviations in size or straightness can lead to stick-slip motion, noise, or uneven load distribution.

Part Features and Machining Scope

• Stepped shoulders
• Threaded sections
• Keyway
• Mounting holes

These features increase manufacturing complexity in hardened shafts. Heat treatment can introduce distortion, and poor edge control may affect installation. Even when the main working diameter meets tolerance, transitions and edges still require careful control to protect the bearing block.

For food-equipment applications, burrs and trapped chips are treated as quality risks, not cosmetic issues. Cleaning and edge control are therefore integrated into the process.

Quality and Production Experience

In hardened 440C shafts, most issues are subtle and appear during motion rather than visual inspection. Common examples include local diameter variation, uneven surface finish, or straightness deviation over functional lengths.

Our inspection approach reflects how the bearing interacts with the shaft. Diameter is checked at multiple positions and orientations, surface finish is controlled in the working zone, and straightness is evaluated according to drawing requirements.

• Plan for heat-treatment movement before final sizing
• Verify diameter stability along the working length
• Confirm surface finish where rolling contact occurs
• Deburr and clean all functional transitions

Verification and Documentation

For custom shafts, verification is based on critical-to-quality items rather than general capability. Inspection and material documentation are prepared per project and aligned with customer requirements. This allows engineering, quality, and procurement teams to review compliance efficiently.

• Hardness verification
• Diameter and fit checks
• Surface finish control
• Straightness evaluation

Food-Equipment Handling and Compliance Boundary

The scope of this project focused on material selection, hardness, and dimensional performance for food-equipment use. Full regulatory compliance depends on the complete machine design, operating environment, and customer validation process.

We manufacture shafts to the approved drawing and support clean delivery practices including deburring, cleaning, drying, and protective packaging.

Typical Deliverables

• Project-level inspection records
• Material certificate for 440C stainless steel
• Protective packaging for transport
• Optional handling or installation notes

Clear deliverables reduce ambiguity and support internal approval processes before installation and commissioning.