Machinery will vibrate when something doesn’t sit properly on its base or another part. A 0.2mm gap that you sometimes can hardly see will create thousands of dollars in repairs.
To correct these tiny gaps that are difficult to assess, metal shim washers are used. Metal shims are thin enough that you can get a precise adjustment. At the same time, you can also take small measurements and carry them throughout the assembly process.
This guide will explain why there are various types of metal shim washers, which metal or type is better suited for different jobs. Then, more importantly, where you will really need to use them.
What is a Metal Shim Washer?
A metal shim washer is merely a thin disc that creates precise spacing between parts. Regular washers do more than shim and fill gaps; they are mainly used under bolts to distribute pressure. But metal shim washers will allow you to solve the alignment issues that are problematic in sheet metal, fabricated parts, or even machining work.
Regular washers are 0.5mm to 3mm thick. Ultra thin shim washers start at 0.01mm. This difference becomes important when you are creeping fractions of millimeters overall to align something. stacked aside, you can totally differentiate or dial in the required spacing needed for your assembly.
Types of Metal Shim Washer
The following are the types of metal shim washers:
Flat Metal Shim Washers
The standard round disc with a center hole. These come in available thicknesses from 0.01mm to 1.5mm. You can stack several flat shim washers to achieve your exact thickness. They serve a purpose for simple leveling jobs where you want to raise one side of a machine or maintain consistent separation across a surface.
Slotted Metal Shim Washers
These washers have a slot cut from the outer edge to the center hole. The slots allow you to slide the shim washer onto a bolt without removing the nut. This is a time-saving feature for maintenance or adjustment of equipment already assembled. Slot patterns can be custom-made to facilitate access requirements or when you want the shim washer to compress in specific directions.
Tapered Metal Shim Washers
The tapered shim washers feature one side thicker than the other, creating an angle. These shim washers compensate for surfaces that are not ore or equipment mounted on a slope. The taper angle varies depending on how much adjustment is required. They are often used in structural applications when beams or mounting surfaces are out of line.
Materials Used for Shim Washers
Stainless Steel Shim Washers
- Grade 304 is appropriate for most general applications and has decent corrosion resistance
- Grade 316 is appropriate for marine and/or chemical exposure applications
- Stainless washers hold up well to good strength at different temperature ranges
- Will not rust in outdoor and/or humid applications
Brass Shim Washers
- Non-sparking for explosive environments
- Good electrical conductivity, when needed
- Softer than steel, so a slight compression is easier
- Naturally corrosion-resistant
Aluminum Shim Washers
- Lightweight considerations in aerospace and automotive racing
- Aluminum has good thermal conductivity for heat transfer needs
- Resists corrosion without any coatings
- Lower cost than stainless steel
Carbon Steel
- Highest strength for heavy loads
- Cost-effective option when needed in large quantities
- Needs coating/plating to prevent rust
- Standard material choice for indoor use in industrial applications
Copper
- Superior electrical and thermal conductivity
- Common when constructing electrical connections and heat exchangers
- Softens with high temperatures
- Usually a higher price than other options
Specialty materials like titanium are used for extreme applications in aerospace. Phosphor bronze material is used in environments with high wear.
Applications of Metal Shim Washers
- Machinery Installation: Installers put metal shim washers under the mounting feet of the equipment to eliminate wobble and vibration. This is critically important for CNC machines, or they cut parts incorrectly.
- Motor and Pump Alignment: Electric motors couple to pumps through shafts that must line up within thousandths of an inch. Misalignment can burn out bearings and seals. Technicians can use ultra thin shim washers that are placed underneath the feet of the motor to achieve perfect shaft alignment.
- Bearing Preload: Tapered roller bearings need to have specific spacing in order for the bearing to function properly. If the spacing is too loose, the bearings will rattle and make noise. If the spacing is too tight, the bearings will overheat and fail. Metal shim washers are used to set the exact preload while the bearing is being assembled.
- Optical Equipment: Microscopes, telescopes, and laser systems will all have components that need to be positioned within microns of clearance. ultra thin shim washers will also be used to achieve that level of fine adjustment.
TMNetch: Custom Metal Shim Washers
TMNetch is a manufacturer of custom metal shim washers manufactured by photochemical etching. This method produces ultra thin shim washers with tolerances of ±0.025mm, beyond the capabilities of stamping.
Material Options Available
- Stainless steel shim washers – grade 304, grade 316, and grade 430
- Aluminum alloys – 6061 or 5052
- Brass and copper – electrical
- Specialty alloys – extreme conditions
Thickness Range
From 0.01mm ultra-thin up to 1.5mm. Any thickness within the range may ship without custom tooling costs.
Customizable Features
- Slots, tabs, or cutouts in almost any configuration
- Multiple holes – your specific bolt pattern
- Logos or number designation directly etched on the shim
- Formed or bent shapes instead of flat discs
Production Process
Most orders ship within 3 days. Whether a small prototype quantity or a large quantity production run, TMNetch can accommodate. No minimum order quantity makes custom metal shim washers ideal for a single machine repair and full production runs.
The company is ISO 9001:2015 certified. Along with the central inspection report and materials certificates, all orders for aerospace, medical, or other regulated industries will include.
Contact TMNetch with your technical drawings, preferred materials, and quantities for a more accurate quote.
FAQs About Metal Shim Washers
Is a shim the same as a washer?
Not quite. Both are thin discs, but they have different functions. Washers help distribute bolt load and protect surfaces. Shims help create specific spacing. A metal shim washer serves a dual purpose.
What is the difference between a flat washer and a shim washer?
Flat washers are typically going to be thicker and designed to control clamping forces. Shim washers are shallower, or thinner, and used for small adjustments. You can stack shim washers to finely adjust to various tolerances.
What are the disadvantages of shims?
If you use multiple shims stacked on top of each other, you increase the area for corrosion to build up in additional interfaces. In a high vibration environment, stacked shims may see uneven compression over time and require adjustment periodically.
What is the best material for shims?
Stainless steel shim washers will work in most circumstances because they resist corrosion and provide strength. Aluminum should be used when weight is a consideration. Ultimately, the best material depends on your operating circumstances.
Conclusion
Proper spacing prevents the malfunctioning of equipment and extends machine life. Which type you choose, whether it is stainless steel shim washers, brass, or aluminum shim washers, depends on your environment and specific needs. TMNetch’s photochemical etching manufactures the metal shim washers on demand that meet the precision and quality standards you or your applications demand.