Key Quality Standards to Know as a Ball Screw Supplier
The quality control of Ball Screws needs to focus on the core dimensions, the following analysis from four key aspects of the quality standards that suppliers must master:
Material and Durability
Base material selection:
The main material is high purity bearing steel (e.g. GCr15), vacuum quenching + deep cooling treatment, surface hardness of HRC58-62, wear-resistant life than ordinary steel to enhance more than 50%, suitable for high-frequency movement scenarios.
Stainless steel (e.g. 440C) for corrosive environments, need to pass the salt spray test (500 hours without corrosion); titanium alloy or ceramic for lightweight scenarios, titanium alloy screws halve the weight but the strength remains unchanged, and ceramic ball rollers are suitable for high speed and low heat demand.
Surface treatment:
Diamond-like coating (DLC) such as "diamond armor", high hardness, low friction, can extend the life of the screw 3-5 years;
Ion nitriding process forms a hardened layer on the surface, which improves the fatigue strength by 60% and is suitable for heavy-duty working conditions.
Precision and transmission performance
Positioning accuracy:
Accuracy level from high to low is divided into precision level (such as JIS 1 level, error ±3μm/m, used in semiconductor photolithography), industrial level (such as JIS 3 level, error ±8μm/m, used in precision machine tools), general level (error ±23μm/m, used in automated production lines).
Testing needs to be done in a constant temperature environment with a laser interferometer to ensure that the nut movement distance deviates very little from the theoretical value, similar to "no more than 1/10 of a hair's breadth error over millimeter-level distances".
Transmission efficiency and noise:
High-efficiency transmission requires low friction, high-speed scenarios need to reach an efficiency of more than 95% (such as electronic mounter equipment), heavy-duty scenarios not less than 90%;
Precision equipment with screw noise needs to be controlled below 55 decibels (close to whispering), ordinary industrial grade not more than 75 decibels (similar to the office background sound).
Third, load and environmental adaptation
Load capacity:
Need to verify the anti-deformation ability of the screw under the maximum load, for example, the machine tool screw needs to withstand tens of tons of cutting force, the safety factor is not less than 2.5 (reserved 2.5 times the safety margin).
The life test simulates actual operation, and the wear of high-end screws should be less than 0.01mm (about the thickness of a piece of paper) after 8000 hours of operation.
Extreme environment adaptation:
High-temperature scenarios (such as oven equipment) need to be able to withstand constant temperature operation of more than 80°C, with accuracy fluctuations of no more than 10%;
Semiconductor and other clean environments, screws need to be certified by the clean room, the surface of the particle pollution is very small (similar to the operating room cleanliness standards), the grease with special materials to avoid volatile pollution.
Fourth, industry adaptation and testing and certification
Breakdown of scene standards:
Medical equipment requires biocompatible materials (e.g., stainless steel + food-grade grease) that can withstand high-temperature sterilization;
Aerospace requires radiation resistance, lightweight (titanium alloy accounted for more than 60%), the material needs to pass the stringent certification.
Quality testing and traceability:
The whole process of testing includes raw material hardness, machining dimensional accuracy, precision calibration after assembly, and each screw needs to have a unique number and test report to ensure that problems can be traced;
CE, ISO and other certifications are required for international markets, and SEMI standards are required for high-end fields (such as semiconductors).
