In industrial machinery, precision is more than a performance goal – it’s a necessity. Misalignment in machines doesn’t just affect output; it accelerates wear, causes inefficiencies, and leads to costly breakdowns. This is where shims- small, precise spacers-play a critical role.
At Datum, we manufacture precision shims designed for use under the feet of machinery or tooling, addressing challenges posed by slightly uneven surfaces. While often associated with adjusting height or levelling equipment, shims are also vital in aligning components within the machine itself, ensuring that shafts, housings, and mechanical parts interact exactly as intended.
Each shim is custom-cut to match the exact footprint of your machine’s pillar, post, or mounting surface, enabling micro-adjustments that ensure optimal stability and alignment. This attention to detail supports long-term accuracy, reduces mechanical stress, and helps maintain critical tolerances throughout the machine’s operating life.
What Are Shims in Machine Alignment?
Shims are thin, flat materials-usually metal or composite-used to fill small gaps, adjust spacing, and align components. In machine alignment, they are inserted between mating surfaces or beneath machine feet to achieve the correct positioning.
In many industrial settings, shims are used during:
- Machine installation and levelling
- Component realignment after maintenance
- Correcting thermal growth or load shifts
- Fine-tuning internal tolerances in complex assemblies
Beyond Height: The 3D Role of Shims
Here’s how shims help align within the machine:
- Axial Alignment
Shims help centre shafts and rotors along their intended axis. Misalignment along the shaft axis can cause vibration, coupling stress, and bearing failure. Shimming ensures proper axial alignment between gearboxes, pumps, motors, and driven equipment. - Lateral/Horizontal Positioning
Components like guide rails, cams, and housings must be precisely located along the horizontal plane. Shims enable small, controlled shifts to ensure clearances, parallelism, and gear mesh are within spec. - Angular Adjustment
Angular misalignment-whether tilt or skew-can be corrected by using shims of varying thicknesses at strategic points. This is critical in aligning surfaces like machine tool spindles or robotic arms to ensure accurate movement and load transfer.
Why Machine Alignment Is Critical
Misalignment might not be visible to the naked eye, but its effects are anything but invisible. Common issues resulting from poor alignment include:
- Increased vibration and noise
- Premature bearing, seal, and coupling failures
- Overheating of components
- Reduced energy efficiency
- Unexpected breakdowns and downtime
These issues compound over time, leading to expensive repairs and lost productivity. In contrast, precision alignment with the proper use of shims enhances equipment health, performance, and reliability.
The Role of Shims in Precision Alignment
Shims allow technicians to make fine, consistent, and repeatable adjustments during the alignment process. Key advantages of using alignment shims include:
- Accurate Corrections
Even a few thousandths of an inch can impact performance. Shims allow exact height adjustments to bring machinery into precise alignment. - Reduced Equipment Stress
Proper alignment minimises stresses on rotating parts, reducing wear and extending the life of bearings, seals, and couplings. - Enhanced Safety
Poorly aligned machines are unpredictable. Precise shimming supports safer operations by lowering the risk of catastrophic failure. - Time & Cost Savings
Technicians can make fast adjustments minimising downtime.
Material Matters: Choosing the Right Shim
Metal shims are ideal for heavy-duty, high-load, or high-precision industrial applications.
Choose your shim material based on the environment, load, and specific machine requirements.
- Stainless Steel
- Most common material for industrial shims
- Resistant to corrosion and wear
- High strength and stability Suitable for harsh or outdoor environments
- Carbon Steel
- Strong and cost-effective
- Often used in static, non-corrosive environments
- Can rust if not treated or coated
- Brass
- Good corrosion resistance
- Easy to machine or cut
- Often used in electrical or non-sparking applications
- Aluminium
- Lightweight and corrosion-resistant
- Easier to shape and adjust
- Not as strong as steel but useful for lighter machinery
- Copper
- Excellent thermal and electrical conductivity
- Used in applications where grounding or heat transfer is a factor
Choose your shim material based on the environment, load, and specific machine requirements.
Best Practices for Using Alignment Shims
- Use precision-cut shims to ensure accuracy and repeatability
- Keep contact surfaces clean to avoid introducing contaminants
- Measure gaps and clearances with micrometres or digital callipers
- Avoid stacking too many shims—choose the correct single thickness when possible
- Document shim usage in your design specs and maintenance logs
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Need Precision Shims for Your Machines?
Tolerances are incredibly tight when it comes to machine fitting, and even the slightest unevenness in the floor or foundation can lead to alignment issues, vibration, and premature wear. At Datum, we provide high-quality, laser-cut and custom-fit shims engineered for critical machine alignment tasks-both external and internal. Whether you need stainless steel slotted shims or bespoke thicknesses for complex assemblies, we can help.