Meeting tight tolerances is a vital part of CNC machining for the rail industry. Read on to find out why these tight tolerances are so important, and how CNC manufacturers like us achieve them.
What are tolerances in rail machining?
A tolerance is the level of accuracy a machined part is required to have. Whilst CNC machining is the most precise manufacturing method available, no part can be made 100% accurate.
Giving a part a specific tolerance gives a margin of error that the part can be manufactured within without compromising its function or safety. For precision engineers, this is especially important in the rail sector.
Why are tight tolerances given?
Especially tight tolerances for part manufacture are usually given when:
- Two or more components are designed to fit or connect (“mating parts”).
- The part is one component of a complex, intricate assembly.
- The part is safety-critical.
How do we achieve tight tolerances?
At M-CNC we achieve tight tolerances in the machining of rail parts in several ways.
1. CAD/CAM programming
We use sophisticated CAD/CAM software at every stage of component manufacture and design. Integrated with our CNC machines, CAD (computer-aided design) software ensures every part we make is manufactured to an incredibly high degree of accuracy. A completed design is turned into machine language, which in turn directs the timing, cutting paths, and speed settings of the CNC machines that will be used to create the part.
CAD/CAM programming offers many advantages for the manufacture of railway parts. It enables unparalleled design flexibility and real time editing, simulation testing to ensure parts will behave as expected in extreme environments, prototyping, and streamlined, efficient workflows.
2. CMM inspection
CMM measurement is a vital part of our quality inspection processes. Our industry-leading coordinate measuring machines (CMMs) also enable us to machine parts to the tight tolerances demanded by the rail industry. We use our CMMs to test that every part we manufacture meets the intent of the original design.
CMMs measure the physical geometry of even the most complex components to an incredibly high degree of accuracy. Testing parts in this way ensures there are no unexpected changes from the original design which could lead to unexpected quality issues.
3. Quality control
The manufacture of components using precision engineering is critical to rail safety. Axles, brake housings, bogie parts, couplings and more are crucial rail components where even small deviations can have serious safety consequences.
To ensure our components meet the tight tolerances rail safety demands, M-CNC employ incredibly robust quality control practices. As well as CMM measuring, we also:
- Provide full material traceability on every part we manufacture, including First Article Inspection (FAI) reports.
- Employ RISQS verified methods that fully meet all rail industry risk assessments and regulations.
- Have attained AS9100 accreditation, which incorporates ISO 9001, attesting to the resilience of our Quality Management Systems and supply chain.
