Key takeaways
- Covers M3 to M12, handling most fastener needs in one purchase
- 304 stainless resists oxidation far better than plain zinc-plated steel
When a project calls for a bulk supply of fastener washers, the 600-piece pack has become the standard unit for contractors, shop owners, and serious DIYers. The range of options spans stainless steel flat washers, nylon plastic variants, internal tooth lock washers, plaster rings, and split lock washers in M20 diameter — all sold under the same “best washers under 600” search intent. Sorting through them means understanding material properties, profile geometry, and whether a particular pack actually solves the problem in front of you.
Good washers distribute load evenly, resist corrosion over years of service, and fit their mating fastener without play. Bad ones strip under torque, oxidize within months, or come in sizes that are slightly off — enough to cause a sloppy connection or a cracked drywall face. This roundup compares published specifications, listed prices, and aggregate owner feedback across eight 600-count washer packs available in 2026, so you can match the right product to the right job.
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Quick Picks
| Product | Best For | Price |
|---|---|---|
| 600 PCS 304 Stainless Flat Washers | General industrial and home repair | $6.79 |
| 1″ Internal Tooth Lock Washers | High-vibration locking applications | $960.99 |
| Cunhill 600 Plaster Washers | Wall and drywall anchor repairs | $24.99 |
| YOUFEN 600 Pcs Nylon Flat Washers (A) | Electrical and chemical isolation | $6.55 |
| Peohud 600 Plaster Washers | Ceiling and drywall fastening | $14.99 |
| YOUFEN 600 Pcs Nylon Flat Washers (B) | Budget multi-size nylon kits | $7.55 |
| M20 Split Lock Washers | Heavy machinery bolted joints | $464.99 |
| 600 Pcs 45 mm Foam Board Washers | Rigid insulation panel fastening | $19.49 |
How We Picked
We evaluated each pack on four criteria: material grade and corrosion resistance as stated by the manufacturer, size range relative to the task it claims to serve, price per piece across the full quantity, and consistency of owner-reported fit and finish. A washer that looks correct on a spec sheet but splits during installation or rusts within a season fails regardless of how inexpensive it is.
The 8 Best Washers Under 600 in 2026
600 PCS 304 Stainless Steel Flat Washers Assortment Kit
This seven-size assortment covering M3 through M12 is the most versatile option in the group. It suits maintenance shops, general contractors, and homeowners who need a single kit spanning common bolt diameters. The 304 stainless designation means adequate corrosion resistance for indoor and moderate outdoor use. Owners consistently praise the organized compartment packaging that keeps sizes separated. The main limitation is that 304 grade is not marine-rated, so saltwater exposure shortens its life significantly.
- Covers M3 to M12, handling most fastener needs in one purchase
- 304 stainless resists oxidation far better than plain zinc-plated steel
Skip this if your application involves constant salt spray or you need a single high-volume size rather than an assortment.
1″ Internal Tooth Lock Washers, Steel, Zinc Plated, 600 Pack
Internal tooth lock washers bite into both the bolt head and the mating surface, resisting rotational loosening. This pack targets industrial assembly where vibration is chronic — machinery frames, conveyor hardware, and equipment mounting. The zinc plating adds a baseline corrosion barrier, though owners in humid climates report surface rust appearing sooner than they expect. The one-inch inner diameter fits a specific shank range, so confirm compatibility before ordering in bulk.
- Teeth provide genuine anti-rotation force that flat washers cannot match
- Zinc plating offers entry-level protection at minimal cost
Skip this if your joints see moisture regularly or if you need a non-marking solution on finished surfaces, since the teeth dig into both faces.
Cunhill 600 Pieces 1 Inch Plaster Washers
Plaster washers are wide-profile rings that spread a screw’s clamping force across a large area of brittle wall material. Cunhill’s zinc-coated versions suit drywall anchor repositioning, masonry plug backing, and general wall repair where a bare screw head would tear through the face. Owners appreciate the generous outer diameter relative to the 1-inch inner bore. The zinc finish, however, is thin enough that cutting through it during driving exposes raw steel underneath.
- Wide profile prevents pull-through on soft substrates
- Zinc coating provides sufficient protection for concealed applications
Skip this for exterior use or visible installations where long-term rust staining is unacceptable.
YOUFEN 600 Pcs 10 Sizes Nylon Flat Washers (Lower Priced Listing)
Nylon washers excel where metal is problematic: electrical isolation, chemical resistance, and preventing galvanic corrosion between dissimilar metals. This ten-size pack gives flexibility for light-to-moderate fastening in electronics enclosures, plumbing fittings, and lab setups. At its listed price, the per-piece cost is among the lowest here. The tradeoff is load capacity — nylon creeps and deforms under sustained high torque, so these are not structural fasteners.
- Non-conductive and chemically inert across a wide range of environments
- Ten sizes in one kit reduces the need for multiple purchases
Skip this if the joint carries significant shear or tensile load, as nylon will deform over time under stress.
Peohud 600 Pcs 1 Inch Plaster Washers
Peohud’s metal plaster washers fill the same niche as the Cunhill option but at a lower price point. They serve ceiling tile repairs, drywall patching, and situations where a screw must be anchored without cratering the surrounding material. Owners note a slightly rougher surface finish compared to premium alternatives, which matters if the washer sits behind trim or in a visible location. For concealed work, the finish is irrelevant and the cost advantage holds.
- Widely available and easy to source in replacement quantities
- Competent performance for standard interior wall and ceiling repairs
Skip this if you need a smooth finished edge or are working on high-visibility installations where surface quality shows.
YOUFEN 600 Pcs 10 Sizes Nylon Flat Washers (Higher Priced Listing)
This is the same product family as the previous YOUFEN listing at a slightly different price tier, which occasionally reflects packaging, seller, or minor production-batch differences. It retains the same ten-size range and nylon composition. For buyers comparing listings side by side, the practical difference is minimal. If both are available, the lower-priced option above delivers identical function. Choose this only if the higher-tier listing ships from a preferred warehouse or offers faster delivery to your location.
- Identical versatility and chemical resistance as the sister listing
- May offer logistical advantages depending on seller and region
Skip this if you have already sourced the equivalent lower-priced YOUFEN pack — paying more here gains no material advantage.
M20 Split Lock Washers, Steel, Zinc Plated, 600 Pack
Split (helical) lock washers create spring tension that resists joint loosening under moderate vibration. At M20 inner diameter, these fit large structural bolts used in equipment bases, steel framework, and heavy machinery. The zinc finish handles indoor industrial environments adequately. Owners note that spring force varies noticeably between individual pieces in a bulk pack, which can lead to inconsistent clamping on critical joints. For mission-critical connections, pairing with a prevailing-torque nut is common practice.
- Effective anti-loosening mechanism for bolted joints experiencing periodic vibration
- Large size range suits heavy-duty structural applications
Skip this for fine-thread or low-torque fastening; an M20 washer is oversized and ineffective on smaller hardware.
600 Pcs 45 mm White Plastic Washers for Foam Board Fasteners
These wide-diameter polypropylene washers are purpose-built for securing rigid foam insulation boards to walls and roofs. The 45 mm spread distributes fastener pressure across the foam face, preventing the screw head from punching through. White coloration blends with common insulation boards. Owners report good performance in new construction and retrofit work alike. The plastic, however, becomes brittle in extreme cold and can crack during driving if the screw angle is off.
- Specifically designed to prevent foam pull-through, a common insulation failure mode
- Polypropylene resists moisture and will not corrode
Skip this for applications outside insulation fastening; the oversized profile and plastic material offer no advantage on standard mechanical joints.
Buying Guide
Material and Corrosion Resistance
The single most consequential spec is material grade. 304 stainless handles indoor humidity and occasional outdoor exposure without visible degradation. Zinc-plated steel adds a sacrificial coating that degrades once scratched, making it suitable for concealed or dry applications. Nylon and polypropylene eliminate corrosion entirely but trade away load capacity. Match the environment first, then choose geometry.
Profile Geometry and Load Distribution
Flat washers spread radial load evenly. Internal tooth lock washers bite into both faces to prevent rotation. Split lock washers use spring tension for the same anti-loosening goal but without marring surfaces. Plaster washers prioritize a wide outer diameter to protect soft substrates. Selecting the wrong geometry means either a joint that loosens or a material that tears — both failures that a 600-pack makes expensive to correct.
Size Compatibility and Pack Rationality
Confirm that the inner diameter matches your actual bolt shank, not just the nominal thread size on the label. A washer with even slight oversize play rotates under torque and defeats its purpose. Assortment kits offer flexibility but sacrifice per-piece pricing compared to single-size bulk packs. If you consume one size repeatedly, a dedicated bulk listing wins on cost.
Our Verdict
Top pick: the 600 PCS 304 Stainless Steel Flat Washers assortment, which delivers broad size coverage, reliable corrosion resistance, and a price that makes it low-risk to keep on hand. Budget pick: the lower-priced YOUFEN Nylon Flat Washers pack at $6.55, offering ten sizes and chemical inertness at a per-unit cost that is difficult to match. If your work is vibration-heavy and requires locking force on large bolts, the M20 Split Lock Washers outperform every flat-washer option in this group despite the higher price.
FAQ
Is “under 600” about price or pack size?
In this context, 600 refers to the piece count per pack. All eight products contain 600 washers, and their prices vary widely based on material, size, and market conditions.
Can nylon washers replace metal in outdoor applications?
Nylon resists water and UV better than zinc-plated steel, but it lacks the compressive strength of metal. Use it where corrosion matters more than load capacity, such as cladding fasteners or ventilation hardware.
Why do split lock washers and internal tooth washers both exist?
Split washers grip through helical spring tension and work best on smooth surfaces. Internal tooth washers bite into both faces and suit softer materials. Neither is universally superior; the correct choice depends on surface hardness and available clamping space.
Do I need to replace washers when removing a bolt?
For flat washers, no — they can be reused indefinitely if undamaged. Lock washers (split and internal tooth) lose their effective tension after a single compression cycle and should be replaced on every reassembly.
