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If you have ever snapped a cheap bolt while tightening it, you already know why the 8.8 stamp on the head matters so much. That little marking means the fastener is made from alloy steel that has been heat-treated to a specific strength standard, so it holds under load instead of stretching or shearing off. This guide cuts straight to the nine 8.8-graded kits worth your bench space, sorted by what each one actually does well.
I’m Min — the founder and writer behind Gadgets Feed. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
You will see the difference between a hobbyist assortment and a kit built for real repairs, plus how thread pitch and diameter affect fit. Every pick below carries the Grade 8.8 rating, so the real question becomes which one matches your bolt drawer — and that is exactly what this guide to the 8.8 bolt covers in plain terms.
Our Picks at a Glance
How To Choose The Best 8.8 Bolt Kit
A bolt kit is only as useful as the sizes inside it and the strength of the steel. Before you pick one, know what you are actually shopping for.
Read The Grade Marking First
Grade 8.8 is a property class stamped on the bolt head, telling you the steel has been heat-treated to a specific strength level. A bolt without that marking may be softer hardware that bends under load. Every kit on this list carries the 8.8 rating, so you can trust the strength before you ever thread one in.
Match Diameter And Thread Pitch To Your Job
Diameter is the width of the bolt shank, and pitch is the distance between thread peaks. An M8 bolt with a 1.25mm pitch will not thread into a hole tapped for 1.5mm, so checking both numbers before ordering saves a return trip. Kits that include matching nuts and washers in the same box remove the guesswork.
Decide Between A Wide Assortment Or A Focused Set
A giant assortment covering M4 through M8 keeps you ready for anything, while a smaller set of just the sizes you use most stays lighter and cheaper to carry. Think about whether you are stocking a garage shelf or grabbing a kit for one specific machine.
Quick Comparison
| Model | Best For | Piece Count | Size Range | Finish | Amazon |
|---|---|---|---|---|---|
| Foliv 1580pcs Metric Bolt Assortment★ Best Overall | Deepest all-round metric kit | 1580 | M4–M8, 12–30mm | Yellow Zinc | Amazon |
| 80Pcs Grade 8.8 M8 Hex Head SetBest Small Kit | One-size canopy and frame fixes | 80 | M8, 30–80mm | Galvanized | Amazon |
| Mywish 791Pcs Grade 8.8 KitBest For Furniture | Bed frames and furniture repair | 791 | M6–M10, 12–50mm | Yellow Zinc | Amazon |
| Twidec 966PCS Metric Bolt Assortment | 3D-print and hobby builds | 966 | M4–M8, 12–30mm | Zinc | Amazon |
| Taiss 966pcs Grade 8.8 Kit | Portable on-the-go repairs | 966 | M4–M8, 12–30mm | Yellow Zinc | Amazon |
| KADRICK 700PCS Class 8.8 Kit | ATV and motorcycle fastening | 700 | M6–M10, 12–45mm | Zinc | Amazon |
| 940PCS M4 M5 M6 M8 Hex Bolts Kit | Automotive and truck work | 940 | M4–M8, 12–30mm | Yellow Zinc | Amazon |
| 705 pcs Metric Bolt and Nut Set | Heavier M10 and M12 jobs | 705 | M6–M12, 15 sizes | Yellow Zinc | Amazon |
| Bonost 1380pcs Nuts and Bolts Assortment | Stackable shop storage | 1380 | M4–M8, 12–30mm | Yellow Zinc | Amazon |
In‑Depth Reviews
1. Foliv 1580pcs Metric Bolt Assortment, M4 M5 M6 M8 Nuts and Bolts Assortment Kit, Grade 8.8 Alloy Steel
Our pick — over 4.5★ from 700+ verified ratings; the strongest balance of quality and price.
The 1580-piece powerhouse that makes a mid-repair trip to the hardware store unnecessary.
If you want one box that handles engine work, furniture rebuilds, and everything between, the Foliv 1580pcs Metric Bolt Assortment is the deepest, most capable kit here. It runs the four most-used metric sizes — M4, M5, M6, and M8 — in lengths from 12mm to 30mm, so the matching nut and washer are almost always already in the tray. That is what turns a frustrating “wrong size” moment into a two-minute fix.
You get 1580 pieces in a box that measures 14.9 x 10.9 x 2.75 inches, so you are covered for nearly every common repair. That 1580-piece count is the standout feature, and it is why this kit is the crowd favorite: 4.7 stars across 700+ owners. The Grade 8.8 alloy steel wins people over, and reviews repeatedly note the bolts are true to size and feel heavier-duty than expected. The 1580-piece count is a genuine head-scratcher for a box that size: you open it, count the compartments, and there really are hundreds more pieces than the smaller 80-piece kit that measures 6.74 x 3.9 x 0.87 inches. Buyers report: “Not puffed up with handfuls of worthless crap like so many lower cost assortments.”
Where the small Foliv gap shows up: the box itself is not overbuilt, and a few owners note the threads on some bolts grab a little before seating cleanly. For wood screws and everyday machine screws that is a non-issue. For precision engine tolerance work, you will want to hand-check each bolt before torquing. The kit itself is solid; the packaging is the honest weak link.
M4 to M8 range
- Covers four metric sizes (M4, M5, M6, M8) in 12mm to 30mm lengths — most common repairs covered in one kit.
- Grade 8.8 alloy steel with a yellow zinc finish for corrosion resistance indoors and out.
- 1580 pieces total, neatly sorted in labeled compartments for fast lookups.
- Owners mention the M4–M8 bolts thread true to size and feel heavier than typical hardware-store stock.
no M10 or M12
- The storage box is functional but not rigid — you may want to reinforce or replace it for heavy shop use.
- Some threads grab slightly before seating; check each bolt if you are working to tight tolerances.
- The 4mm groove diameter means smaller diameters — this kit tops out at M8, not M10 or beyond.
stock the shop: You want one deep assortment that covers most everyday metric repairs without a store run.
size gap: You need M10 or M12 hardware, or you plan to heave the box around a job site — the lid will not survive that.
2. 80Pcs Grade 8.8 M8 Hex Head Screws Bolts and Nuts Flat & Lock Washers Assortment Kit
A tidy 80-piece M8-only set for when you already know the exact size you need.
Sometimes you do not want a wall of compartments — you want 20 complete sets of M8 bolts, nuts, and washers in one sturdy box. That is precisely what this YEEZET kit delivers: five lengths (M8x30mm through M8x80mm) with a 1.25mm pitch, which is the match for most standard M8 tapped holes.
You get 24 M8 bolts, which is a small number on paper, but the kit punches above its size because every piece is pre-matched. The plastic storage box is the standout feature here — solid enough to live in a truck bed without cracking. The 8mm diameter is also twice the 4mm groove diameter of the big Foliv kit, so this is the better call when the repair calls for a beefier bolt rather than a wider assortment.
The honest catch: this is not an outdoor kit. YEEZET’s own product page advises avoiding damp environments, and a handful of owners have noted the washers are on the smaller side. For indoor frame repairs and canopy fixes it is exactly right. For a salt-spray or wet-basement job, you want a yellow zinc finish instead.
small repair: You need a handful of matched M8 sets and a compact box you can toss in the truck without worry.
bulk jobs: Your project lives outdoors or in humid air, or you need M10 hardware alongside your M8s.
3. Mywish 791Pcs Grade 8.8 Metric Bolt Assortment Kit – M6, M8, M10 Hex Head Bolts, Nuts and Washers
The bed-frame-and-furniture specialist that skips the tiny sizes and delivers real holding power.
You get M6 through M10 sizes, so this kit covers the frame, bracket, and appliance sizes that actually hold weight. That M10 range is the feature that separates it from every kit that stops at M8, and it is the reason this is the practical choice for anything a body will lean or sit on.
What owners love is the precision of the thread cuts. Grade 8.8 alloy steel with yellow zinc plating means these hold up indoors and out, and the labeled dividers in the case make finding a matching nut quick. The thread pitch is also correct at 1.25mm for M8 and 1.5mm for M10 — the numbers that make the difference between a bolt that threads in cleanly and one that fights you the whole way.
The trade-off is real but narrow: the smaller M6 sizes have some play in the fit, and a couple of owners noted that some screws and nuts feel slack. That is a fit-mismatch issue rather than a quality one, and it rarely matters for the frame work this kit is built for. If you are assembling precision instrumentation rather than furniture, go tighter on your thread tolerances.
791 piece count: Anyone tightening a bed frame, repairing a piece of furniture, or bolting down equipment that needs to hold steady. The M10 option is the differentiator.
M6 and M8 only: Skip this if you need a full spread of M4 and M5 sizes — the Mywish set is deliberately focused on the heavier mid-range, not the tiny hardware.
metric starter: Your project needs M10 holding power and a clearly organized case you can open and read at a glance.
large sizes: You want a wide range of tiny M4 and M5 fasteners instead of the heavier mid-range sizes.
4. Twidec 966PCS Metric Bolt Assortment, Grade 8.8 Hex Head Bolts and Nuts Kit
The 3D-printing maker’s kit — nineteen sizes that match the hardware most printed projects are designed around.
Print a mounting bracket, drill the holes, and reach for a Twidec bolt. This 966-piece set spans nineteen sizes across M4, M5, M6, and M8 with lengths from 12mm to 30mm, which is the same range most printed and hobby projects are modeled to accept. The clear compartment box keeps each size separate, and it doubles as a grab-and-go toolbox for the workbench.
The threads cut clean and the gold zinc coating resists rust while looking better than the usual dull gray finish. Customers note the 19 sizes fit 3D-printed assemblies cleanly, and the per-piece cost undercuts most 966-piece kits.
The one thing to plan around: a few boxes arrive with light oil on the pieces and an occasional mixed compartment, which is a quick wipe-and-sort before the first job. None of that affects how the bolts perform, and it is the sort of packaging nit that clears itself up after an hour of organizing.
5. Taiss 966pcs Grade 8.8 Metric Bolt Assortment, M4 M5 M6 M8 Heavy Duty Hex Bolts and Nuts Kit
A 5.39-pound case you can actually carry to the job, not just park on a shelf.
You can carry 966 pieces across nineteen sizes — M4, M5, M6, and M8 in 12mm to 30mm lengths, with nuts, flat washers, and lock washers for each — in a handheld box with labeled compartments and a proper handle. That handle is the reason this kit goes to the project instead of the project coming to the kit.
At 5.39 pounds it is heavy enough to feel substantial and light enough to lug up a ladder in one hand. The galvanized finish resists rust and stands up to wet, outdoor, and slightly corrosive conditions, so a truck bed or a shed shelf is fine. The 966 pieces break down to roughly 235 bolts in varying lengths and matching nuts and washers for each — enough that you rarely finish a repair and find yourself one short.
If there is a small frustration, it lives in the labeling rather than the hardware: the compartment stickers line up correctly once you sort them, but a few owners have found the case arrives with pieces shifted out of their slots after shipping. A quick sort on arrival solves it, and from then on the case stays organized.
M4 through M10: This is the kit for a mobile mechanic, an RV or boat owner, or anyone whose repairs happen away from a fixed workbench.
no M12 bolts: If you never move your fasteners, the fixed Foliv case gives you nearly the same coverage without paying for the carry handle.
mid range kit: Mobile repairs where one trip is the whole point, and a labeled case you can pick up and carry beats an open tray.
big bolt work: You want the largest piece count per box — the Foliv kit edges past this one on total hardware.
6. KADRICK 700PCS Class 8.8 Metric Bolt Assortment, M6 M8 M10 Flange Hex Bolts
Flange-head bolts with a deliberately tighter thread pitch — the choice for vibration-prone machinery.
You get 175 pieces each of bolts, nuts, flat washers, and spring washers for a total of 700 parts, weighing over eight pounds of hardware. Flange head bolts spread load over a wider bearing surface, which is exactly why KADRICK uses them on its M6, M8, and M10 hardware. There are also serious strength credentials here: a rating of 8.8, a maximum shear strength of 400 N/mm², and a 1.25mm thread pitch on the M8 (rather than the 1.5mm found on some competing kits) — the tighter spec means less thread slop under load.
The trivalent chromate plating is the other standout, providing strong rust resistance while avoiding the harsher coating chemistry that some shops prefer to skip. That makes it well suited to ATVs, motorcycles, and any assembly that gets rained on or mud-splashed. The labeled plastic box keeps things tidy, and Kadrick adds a 24-month warranty to back the strength claim.
The one thing to plan around: some owners note that the M10 fit is not as tight as they expected on certain tapped holes. It is a fit-specific mismatch — usually to the bolt diameter rather than the kit — and for the ATV, motorcycle, and powersports jobs this kit is designed around, it rarely matters. The 8mm compatible groove diameter is your reference when picking which bolts fit which holes.
7. 940PCS M4 M5 M6 M8 Metric Hex Bolts Assortment Kit, Length 12mm-30mm
A perfectly balanced 235-of-each kit — bolts, nuts, flat washers, and spring washers in matched counts.
What sets this 940-piece kit apart is the math: 235 bolts in 18 different sizes, 235 nuts in 4 sizes, 235 flat washers in 4 sizes, and 235 spring washers in 4 sizes. That equal four-way split means you are never rummaging for the matching hardware mid-job, and it is why owners keep reaching for it on 90s truck and general automotive repairs. The standard hex head with clear threads distributes force evenly, so you get a precise grip without stripping.
The yellow zinc plating is the corrosion protection of choice here, and it holds up better than a plain finish in a truck bed or a garage that sweats in winter. The Grade 8.8 alloy steel resists corrosion and stands up to wear without bending under heavy load — the exact performance you want when a bolt is under a manifold or suspension bracket. The 10.04 x 8.27 x 1.56 inch clear divided case keeps every size visibly separated, and the outer gift-ready box means it does not look like a junk drawer.
The honest gripe: a lot of tiny M4 and small washers take up tray space, and some owners would trade them for more larger sizes. You also get a case that occasionally arrives with the lid feeling flexy — the dividers inside are the real strength, not the shell. Both are minor, and if you mostly reach for M6 and M8, you may find yourself wishing the kit was a touch more focused.
length variety: Wants the tightly balanced bolt/nut/washer ratio for cars, trucks, and everyday machinery.
nuts missing: If your projects lean large-diameter, the tiny M4 pieces here are filler you will not touch.
8. 705 pcs Metric Bolt and Nut Set – M6/M8/M10/M12 Class 8.8 Heavy Duty Hexagon Bolts and Nuts Assortment Kit
The only kit here that goes up to M12 — the big-bolt option for chassis and structural work.
Most 8.8 assortments top out at M10. This LUPANTER set is the exception, running M6 through M12 across fifteen common sizes in 705 pieces, which makes it the pick when a repair calls for a genuinely heavy bolt. The yellow zinc plating adds a layer of corrosion protection, and the plastic case separates each size and type so you are not digging through a jumble when you need one specific piece.
Land Rover owners, in particular, have found this kit useful for replacing a lower steering shaft bolt without a trip to the shop. That is the whole case for a broad metric kit: when the correct bolt is already in the box, a Saturday repair does not turn into a Monday problem. The set includes locking washers and flat washers alongside the bolts and nuts, so a rebuild with new hardware on every fastener is realistic.
The fair warning is on the washers. A portion of the 705 pieces are lock washers rather than additional bolts, and some owners have found the lock and flat washers tightly captured on individual bolts — they need a firm pull to separate. For the price-per-bolt, the count still works out well; just know half your total is in the washer column.
M12 bolts inside: This is the kit that covers the sizes the M10-max sets cannot reach, which makes it the right call for anything structural, chassis-mounted, or heavy-duty.
washers not included: The 705-piece headline includes a generous count of lock and flat washers, so the bolt-only count is lower than the number suggests.
heavy duty: You work on trucks, farm equipment, or anytime the job needs M10 or M12 holding power.
washer needed: You only need M6 and M8 sizes — the extra money here is going into bigger hardware you may not use.
9. Bonost 1380pcs Nuts and Bolts Assortment Kit, Zinc Plated, Grade 8.8 M4-M8
A stackable, handle-topped 1380-piece kit built to keep a shop shelf from turning into a junk drawer.
The storage design is the headline here. Bonost ships 1380 pieces — 345 metric hex bolts in 19 sizes across M4, M5, M6, and M8, plus 345 nuts and 690 lock washers — inside an upgraded stackable case with handles. The stackable feature means a shelf of multiple kits lines up neatly instead of tumbling, and the fastener guide printed in the lid makes finding one specific size fast. That organization is what keeps a big assortment actually usable instead of a lost cause.
The steel itself is carbon steel with a grade 8.8 rating, zinc-coated for rust and corrosion protection. That combination handles the everyday jobs — machinery repairs, furniture work, backyard sheds — without rusting in a damp garage. And because the nut and washer counts are matched to the bolt counts, you can rebuild an entire piece of furniture with fresh hardware and still have a full tray left over.
What you are not getting is the tightest tolerance on the market. Some owners have found that the flat washers and lock washers arrive needing a firm pull to free them from the bolts. It is a quickly solved annoyance, not a hardware flaw — once sorted, this kit will serve your shop for years.
1380 piece count
- Stackable case with handles and a printed fastener guide — genuinely easy to organize and find the piece you need.
- 1380 pieces total, with full matching nuts and washers for every bolt size.
- Grade 8.8 carbon steel with zinc coating that resists rust in damp conditions.
- Owners describe the stackable case as sturdy enough to sit on a shop shelf without cracking.
zinc plating only
- Washers can arrive tightly captured on individual bolts and take some effort to separate.
- Skipping M10 and larger diameters means this is not the pick for heavy chassis work.
- Two cases means two storage footprints if you want the full size range in one go.
bulk refill: Anyone building out a shop or garage who values easy organization and a matched bolt/nut/washer count above all else.
stainless wanted: Projects calling for M10, M12, or a simple single-size kit — for those, look at the LUPANTER or YEEZET sets above.
Understanding the Specs
Grade 8.8 — What The Number Means
Grade 8.8 is a steel property class, not a brand name. It tells you the bolt has been heat-treated to reach a specific tensile strength, so it bends and holds under load instead of shearing. Harder grades like 10.9 exist, but 8.8 is the standard for general automotive, furniture, and DIY work. Every kit in this guide carries the 8.8 marking.
Diameter And Thread Pitch — The Two Numbers That Decide Fit
Diameter is the width of the bolt shank (M8 means 8mm across), and pitch is the distance between thread peaks. These two numbers must match the hole you are threading into. An M8 bolt with a 1.25mm pitch will not work in a socket tapped for 1.5mm. Knowing both before you order saves the return trip.
Yellow Zinc Plating — The Rust Protection Layer
Yellow zinc is a thin metallic coating applied after the bolt is made. It slows rust and corrosion the way a primer slows rust on a car panel, which is why kits with this finish hold up longer outdoors and in humid shops. A plain galvanized finish is fine indoors; yellow zinc is the better call for anything that sees wet or damp conditions.
Piece Count Versus Working Hardware
The headline piece count on a kit includes bolts, nuts, and washers combined. A 700-piece kit with 175 bolts gives you those bolts plus 175 nuts and 350 washers split between flat and spring types. Read the breakdown, not just the total, when you are comparing two kits.
FAQ
What does the 8.8 on a bolt head actually mean?
Will an M8 bolt with 1.25mm pitch fit a hole tapped for 1.5mm?
Is yellow zinc plating better than plain galvanized?
Can I use these bolts outdoors in the rain?
What is the difference between flat washers and lock washers?
What size bolt kit should a beginning DIYer start with?
Do these kits include nuts and washers, or just the bolts?
How should I store a large bolt kit so sizes don’t mix?
Can I use 8.8 bolts on my car or motorcycle?
Will the bolts in these kits rust if I keep them in my garage?
Final Thoughts: The Verdict
For most people buying an 8.8 bolt kit, the Foliv 1580pcs Metric Bolt Assortment is the strongest single answer — the crowd favorite at 4.7 stars across 700+ owners, with the widest M4-to-M8 coverage and 1580 pieces that cover nearly every common repair. If you want the tight thread pitch and powersports-ready flange heads, grab the KADRICK 700PCS Class 8.8 Kit. And for repairs that follow you out to a truck or boat, the Taiss 966pcs Grade 8.8 Kit is the one to reach for. If your project lives in the M10 and M12 range, the LUPANTER 705 pcs Metric Bolt and Nut Set earns the spot with the largest diameters on this list.
How We Picked
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of September 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
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