When performance, safety, and reliability are on the line, there’s no room for error. That’s where precision engineering for tight tolerances becomes critical. Whether it’s a shim, washer, spacer, or a custom fastener, manufacturing components to exact dimensions is not just about machinery – it’s about skill, experience, and control.
At Stephens Gaskets, we’ve spent decades mastering the art of producing high-precision components that meet demanding engineering specifications – every time.
Why Tight Tolerances Matter
Tolerances are the limits within which a component’s size, shape, or geometry must fall. In high-spec applications, even a small deviation can cause:
- Misalignment during assembly.
- Reduced part lifespan.
- Heat build-up or vibration.
- Safety risks in critical systems.
That’s why industries such as aerospace, automotive, medical, power generation, and instrumentation demand parts that are not just close – but exact.
Common Tolerance Challenges
Achieving tight tolerances is about more than cutting a part to size. It requires managing several interrelated specifications, including:
1. Flatness
Ensuring surfaces remain level across the component to prevent uneven wear or seal failure.
2. Concentricity
Keeping circular features perfectly aligned around a common centre axis – essential for rotating components.
3. Parallelism and perpendicularity
Maintaining the intended angles between features during forming or machining.
4. Surface finish
Controlling roughness for friction-sensitive applications or sealing surfaces.
Each of these must be balanced without introducing warping, distortion, or residual stress – especially in thin or complex parts.
How Stephens Gaskets Delivers Precision
Our team brings over 75 years of manufacturing experience to the table, supported by equipment and processes optimised for tight tolerance machining and forming.
1. Precision Press Tools
For stamped or pressed parts, tool design is everything. We use hardened steel dies, precision-ground punches, and regularly calibrated tooling to maintain dimensional consistency – batch after batch.
Our power presses range from 6 to 110 tonnes, allowing us to apply just the right amount of force to form the part without distortion.
2. CNC Turning and Machining
For turned parts or special components, we use sliding head and fixed head CNC lathes capable of sub-20 micron accuracy. Live tooling enables us to cut multiple features in one setup, reducing tolerance stack-up.
We machine parts from metals like stainless steel, brass, and aluminium, as well as high-performance plastics such as PEEK, acetal, and PTFE.
3. Laser Cutting for High Accuracy
Our fibre and CO₂ laser cutting systems offer clean, burr-free cuts with tight edge tolerances. This is especially useful for washers, shims, and flat components where inner and outer diameters must meet exact spec.
Material Stability and Fixturing
Achieving tight tolerances also requires managing material behaviour. We understand how different materials react to cutting forces, heat, and stress. Our production team adjusts feeds, speeds, and tooling paths to account for:
- Material thickness and hardness.
- Spring-back during bending or forming.
- Thermal expansion during cutting.
- Stress relief and distortion risk in thin sections.
We use custom jigs, clamps, and vacuum tables to keep delicate parts stable during machining or finishing.
Quality Assurance That Supports Precision
No matter how accurate the machine, the result is only as good as the inspection process. Our quality assurance procedures ensure that every part shipped matches the drawing.
We use:
- Digital micrometers and vernier callipers.
- Surface plates and height gauges.
- CMM (coordinate measuring machine) inspection for critical parts.
- Visual and surface finish checks.
- Batch sample inspection and full traceability.
We are fully ISO 9001:2015 certified, giving customers complete confidence in our process.
Real-World Applications
Our tight tolerance components are used in sectors where precision is mission-critical, including:
1. Aerospace & Defence
Where concentricity and flatness ensure reliable performance under extreme stress.
2. Automotive & Motorsport
For precision shims and washers used in suspension, drivetrain, and powertrain assemblies.
3. Medical & Laboratory Equipment
For machined plastic and metal parts where exact fit and smooth finish are vital.
4. Power Generation
Where thermal expansion and vibration demand tight, consistent tolerances over long-term use.
Examples of Precision Components We’ve Delivered
- Stainless steel shims with ±0.02mm thickness tolerance.
- Brass washers with flatness under 0.03mm across 60mm diameter.
- PEEK machined collars with concentric ID and OD to within ±0.015mm.
- Laser-cut aluminium gaskets with radius and hole tolerances to ±0.1mm.
Whether it’s a one-off prototype or a recurring order, we approach every job with the same commitment to precision engineering.
Why Choose a Specialist for Tight Tolerances?
- Extensive experience in high-precision parts.
- ISO 9001-certified inspection processes.
- Specialist in balancing flatness, alignment, and geometry.
- Advanced tooling and CNC technology.
- Short lead times for urgent technical parts.
FAQs – Precision Engineering
1. What tolerance levels can you achieve?
Depending on the material and process, we can hold tolerances as tight as ±0.01mm.
2. Do you support prototype quantities?
Yes. We specialise in low-volume and one-off precision components as well as production runs.
3. What file formats do you accept?
We accept DXF, DWG, STEP, and PDF files-or can work from sketches or samples.
4. Can I request inspection data or C of C?
Yes. We can supply full dimensional inspection reports and certificates of conformity as needed.
Final Thoughts
When tolerances are tight, experience matters. From flatness and concentricity to precision stamping and CNC machining, Stephens Gaskets delivers with consistency, care, and control. Our focus on precision engineering for tight tolerances gives our customers the performance they need – with the reliability they expect.
Let us help you turn your specification into precision reality.
Ready to Discuss a Precision Engineering Project?
Whether you’re developing a high-spec product or solving a critical application challenge, we can help. Our team works closely with engineers and technical buyers to meet the most demanding specifications – quickly, reliably, and accurately.
Request a quote or talk to a technical expert today:
Phone: +44 (0)121 544 5808
Email: sales@stephensgaskets.co.uk