Washers
Washers spread load, protect surfaces, and help fixings hold properly on timber, steel, and site hardware without pulling through or working loose.
If a fixing is biting into soft timber, thin sheet, or painted metal, this is the bit that stops the job going wrong. Washers sit under the head or nut to spread pressure, reduce marking, and help stop loosening where vibration is a problem. You'll use flat washers for everyday fastening, penny washers where you need more bearing surface, and spring washers when you want a bit more resistance against shake and movement. If you're pairing up Bolts, Nuts, or Set Screws, get the washer size and finish right and the fixing will last longer and hold cleaner.
What Are Washers Used For?
- Spreading the load under a bolt head or nut stops fixings pulling into timber, plastic, or thin sheet when you're tightening down brackets, plates, or framework.
- Backing off soft or damaged holes with penny washers gives you more surface area, which is handy on repair work, cladding, fencing, and site-made timber assemblies.
- Reducing surface damage under fixings helps when you're bolting through painted steel, stainless sections, or finished metalwork you do not want chewed up on install.
- Holding tension on fixings with spring washers helps on plant covers, gates, vibration-prone brackets, and other jobs where movement can gradually work nuts loose.
- Matching stainless steel washers or galvanised washers to the fixing and environment helps prevent premature rusting on outside work, damp areas, and exposed structural details.
Choosing the Right Washers
Match the washer to the fixing and the material you are clamping. That is what stops pull-through, damage, and loose joints.
1. Flat Washer vs Penny Washer
If you just need a standard spread of load under a nut or bolt head, flat washers are the usual pick. If the hole is rough, the material is soft, or the fixing could pull through, go straight to penny washers because the larger outside diameter gives you more bearing surface.
2. Get the Size Right
Do not guess. M8 washers are made to suit M8 fixings and m10 washers suit M10 bolts or studs. Too small and they will not seat properly. Too large and the fixing can sit sloppy, especially on brackets or slotted holes.
3. Match the Finish to the Job
For outside work or damp conditions, stainless steel washers or galvanised washers make more sense than basic bright zinc. If the fixing is going into exposed timber, gates, roofing details, or external brackets, choose a finish that will not start rusting before the rest of the job has even weathered in.
4. Use Spring Washers Only Where They Help
If the fixing is on kit that shakes, rattles, or sees repeated movement, spring washers can help resist loosening. For a simple static fixing into timber or steelwork, a standard flat washer is usually the better and cleaner choice.
Who Uses These on Site?
- Steel erectors and fabricators use washers every day for bolted connections, brackets, and plates, especially where they need clean clamping force across slotted or oversized holes.
- Carpenters and roofers swear by penny washers on timber jobs because they stop fixings pulling through sheet material, straps, and lighter sections when the load spreads out.
- Fencers, landscapers, and groundworkers use galvanised washers outside on gates, posts, and site-built timber work where weather resistance matters as much as holding power.
- Mechanical fitters and maintenance teams keep spring washers and flat washers to hand for motors, guards, plant panels, and general repair jobs where vibration can be an issue.
- General builders reaching for Nuts, Bolts & Washers will usually stock the common sizes like m8 washers and m10 washers so they are not stuck when a fixing needs packing out properly.
Fixings to Use with Washers
Get the full fixing right, not just the washer, or you will be back tightening and replacing it later.
1. Bolts
A washer is only doing half the job without the right shank and head to suit it. Pair it with the correct Bolts when you need through-fixing strength on steel, timber, brackets, and heavy site assemblies.
2. Nuts
If you are through-bolting, keep matching Nuts on hand so you are not mixing threads or bodging whatever is left in the van. Properly matched threads and washer sizes give a cleaner clamp and a more reliable hold.
3. Set Screws
For threaded holes in steel or machinery, Set Screws and washers are a straightforward combination. They help spread load under the head without needing a nut on the back.
4. Coach Screws
On timber joints, straps, and heavier outdoor fixings, washers under Coach Screws stop the head burying into the timber and give you a neater, stronger pull-up.
Choose the Right Washers for the Job
Here is the quick way to sort what washer suits the fixing and material in front of you.
| Your Job | Washer Type | Key Features |
|---|---|---|
| General bolting through steel plates or brackets | Flat washers | Standard load spreading, cleaner seating under nuts and bolt heads, everyday stock item for common fixing jobs. |
| Fixing into soft timber, sheet material, or oversized holes | Penny washers | Larger outside diameter spreads load wider and helps stop pull-through on lighter or damaged materials. |
| Plant covers, gates, guards, or vibrating assemblies | Spring washers | Adds resistance against loosening where movement and vibration can work fixings back over time. |
| External jobs, damp areas, or exposed metalwork | Stainless steel washers or galvanised washers | Better corrosion resistance for weathered and wet conditions, especially when matched to the fixing finish. |
| Matching common site fixings | M8 washers or M10 washers | Sized to suit the bolt properly so the washer seats flat and clamps the joint without slop. |
Common Buying and Usage Mistakes
- Using a washer that is too small for the fixing means it will not sit properly under the nut or head. The fix is simple. Match the washer size to the bolt size, not to whatever happens to be in the tub.
- Picking flat washers when the material is soft or the hole is worn can lead to pull-through. If you are fixing straps, sheets, or timber with oversized holes, step up to penny washers or repair washers.
- Mixing finishes is where rust starts early. A zinc plated washer on stainless fixings or exposed outdoor work can stain and fail long before the rest of the assembly, so match the washer finish to the fixing and location.
- Using spring washers on every job is a lazy habit and not always the right answer. On static fixings they often add little, so use them where vibration is the real problem, not as a default.
- Overtightening against thin sheet or soft timber can still crush the material even with a washer fitted. If the material is weak, use a wider washer and tighten to a sensible clamp, not brute force.
Flat Washers vs Penny Washers vs Spring Washers
Flat Washers
This is the standard choice for most bolted joints. Flat washers spread load neatly and protect the surface under the fixing, making them the everyday pick for brackets, steelwork, timber joints, and general assembly.
Penny Washers
Penny washers do the same basic job as flat washers but with a much wider outside diameter. They are the better option when the material is soft, the hole is rough, or you need to stop a fixing pulling clean through sheet or timber.
Spring Washers
Spring washers are about resisting loosening rather than just spreading load. Use them on vibrating equipment, moving assemblies, or maintenance jobs where nuts have a habit of backing off over time.
Which One Should You Buy?
For most site fixings, flat washers are the starting point. Go to penny washers when you need more support under the head, and keep spring washers for jobs where movement and vibration are the real issue.
Maintenance and Care
Keep Sizes Separated
Sort washers by type and size in labelled tubs or drawer organisers. Once m8 washers, m10 washers, and penny washers get mixed together, you waste time on every fixing job.
Store Them Dry
Even plated washers will suffer if they sit damp in the back of the van. Keep them in sealed boxes and out of standing moisture, especially if you want bright finishes to stay clean and usable.
Bin Bent or Burred Washers
If a washer is bent, split, heavily rusted, or chewed up round the bore, replace it. Damaged washers do not clamp evenly and can mark the work or let the fixing settle loose later.
Match Replacement Finish
When topping up stock, replace like for like. Stainless steel washers should stay with stainless fixings, and galvanised washers should stay on external assemblies where corrosion resistance matters.
Why Shop for Washers at ITS?
Whether you need standard flat washers, penny washers for repairs, spring washers for moving kit, or common sizes like m8 washers and m10 washers, we stock the range that keeps fixing jobs moving. It is all in our own warehouse and ready for next day delivery, so you can get the right washer on site without holding up the rest of the install.
Washers FAQs
What is a washer used for?
A washer spreads the load from a nut or bolt head so the fixing clamps properly without digging into the material. On site that means less pull-through on timber or sheet, less marking on finished surfaces, and a cleaner, more reliable joint.
What's the difference between a flat washer and a penny washer?
A flat washer is your standard everyday option for spreading load under a fixing. A penny washer does the same job but with a much larger outside diameter, so it is better where holes are oversized, materials are soft, or there is a risk of the fixing pulling through.
When should I use a spring washer?
Use a spring washer when the fixing is on something that vibrates, moves, or gets knocked about, such as plant guards, gates, or machinery covers. For static joints, a flat washer is usually the better call unless the spec says otherwise.
What size washer fits an M10 bolt?
An M10 washer is made to fit an M10 bolt. Sounds obvious, but it is worth checking because bore size and outside diameter both matter. If the washer is undersized it will not seat properly, and if it is too loose it can sit badly on slotted or uneven surfaces.
Are stainless washers better than zinc plated?
For outdoor work, damp areas, or anything exposed, yes, stainless washers are usually the better long-term choice because they resist corrosion far better. Zinc plated washers are fine for many indoor jobs, but they are not the one to trust where weather and moisture are constant.
Can I use one washer size across different bolts if it nearly fits?
You can bodge it, but you should not. A washer that only nearly fits can sit off-centre, mark the material, or fail to spread the load properly. Keep the common sizes in stock and match them to the fixing you are actually using.
