M5 stainless steel penny washers (304) – 50 pack for bolts, screws and outdoor fixes

If you’re tightening M5 screws or bolts and you’re fed up with connections that feel like they might work loose, these 304 stainless steel flat/penny washers are a straightforward bit of hardware to keep in the kit. They’re designed to spread load, add a more stable contact surface and help reduce the chances of loosening over time.

On paper, they’re aimed at practical repairs and assemblies, including outdoor work where corrosion resistance matters. The big question is whether your application benefits from a washer at all—if you’re dealing with soft surfaces, uneven clamping, or you want to protect parts under load, these are the kind of simple upgrade that often makes a noticeable difference.

Key takeaways (what matters most)

These M5 washers come as a small 50-piece pack, in 304 stainless steel, with a stated high-precision size of M5251.5. Their main jobs are to: - provide a larger flat bearing area under the fastener - help disperse the pressure created by tightening - reduce friction and support more secure clamping in assemblies

They’re also positioned for long-term use, including outdoor projects, which is where stainless hardware usually earns its keep.

It’s a sensible buy if you want reliable basic washers rather than experimenting—though it’s worth noting that washers alone won’t replace a proper locking method when your design truly needs it.

What you’ll notice in use

A washer can be the difference between “tight” and “tight that stays tight”. In a typical job, you’d place the washer under the screw head or bolt nut so the metal head/nut sits on a wider surface. That means:

• the load is spread, so the fastener doesn’t bite as sharply into the surface
• the connection experiences less concentrated stress at the contact point

For something like a home mechanical fix, a generator/machine tool component, or an outdoor assembly where moisture and weather are in the picture, having stainless washers makes the whole setup feel less vulnerable to rust and corrosion. The description also points to reduced friction and help with preventing loosening, which fits the everyday goal: fewer re-torques.

Materials and build quality

The washers are made from 304 stainless steel and are described as having stable structure with good corrosion and rust resistance. In practice, that matters because many “cheap washer” problems show up after a while—deformation, surface corrosion, or fasteners feeling like they’re not holding as confidently.

That said, you’re still buying a washer: it’s not a heavy-duty structural component, and it won’t magically correct a mismatch in size, thread, or clamping design.

Tech specs

• Name: M5 Washers for Screws, Penny Washers (50 pcs)
• Type: flat/penny style repair washers and lock washer spacers (stated use with bolts/screws)
• Material: 304 stainless steel
• Size: M5251.5 (as stated)
• Quantity: 50 pcs

Where it shines (and where it may fall short)

This pack makes the most sense for broad, everyday hardware tasks—electrical connections, household/mechanical equipment, home maintenance, automotive and ship applications, generators, machine tools, factories, and outdoor projects are all mentioned.

If you prioritise corrosion resistance for long-term outdoor work, these washers are a fairly practical choice. They also suit situations where you want to protect bolts and parts by reducing friction, helping prevent loosening, and lowering stress at the contact points.

However, don’t expect miracles if your application is high-vibration or requires a specific locking strategy. Depending on how critical the joint is, you may still need the right locking hardware or design features beyond a plain washer.

Compatibility and requirements

These washers are specifically described for M5 screws and bolts. If your fasteners aren’t M5, it’s best to skip—choosing the wrong washer size tends to cause poor clamping and can make things worse rather than better.

It also helps to check whether you need flat load-bearing washers only, or whether your project calls for a different locking approach.

Is it worth it?

Buy these M5 stainless steel penny washers if you’re working on M5 bolt/screw assemblies and you want a 50-piece pack of corrosion-resistant washers to spread load, reduce stress at the contact point, and support more secure connections—especially for outdoor or long-term use.

You may want to avoid them if you don’t have M5 fasteners, or if your setup relies on a more specialised locking method to handle vibration or safety-critical loads. In those cases, washers help, but they’re not the whole solution.

Quick FAQ

What are these washers for?

They’re flat/penny style washers intended for use with M5 screws and bolts to provide a larger bearing surface, help prevent loosening, and protect parts under clamping.

Are they suitable for outdoor use?

The description explicitly frames them for long-term outdoor work, citing 304 stainless steel corrosion and rust resistance.

Do I need a washer if I’m already tightening a screw or bolt?

Not always, but if you’re spreading load across a surface, protecting parts, or trying to reduce loosening over time, adding a washer is often a sensible step.

What size are they?

The stated size is M5251.5.

How many do you get?

There are 50 pcs in the pack.