Cup Head Bolts Carriage Bolts

Cup Head Bolts Carriage Bolts

Carriage Bolts, Coach Bolts, Cup Head Bolts

  • Standard: DIN603, DIN8677
  • Sizes: M5, M8, M10, M12, M16, M20
  • Surface: Galvanized Carriage Bolts, Black Carriage Bolts, Plain Steel Carriage Bolts
  • Grade: 5, 8

Carriage bolts factory and manufacturing company


Black or Galvanized Metric Carriage Bolts Grade 8, Cup Head Bolts

Carriage bolts, also called coach bolts, cup head bolts, which are bolts with a cup head or a mushroom head and square neck. Metric carriage bolts are most common seen in wood applications, metal to wood connection applications.

  • Material: Carbon Steel, Alloy Steel, Stainless Stell, 1008, 1010, 1015
  • Application: Wood application, wood to metal connection
  • Package: Small box, or 25kgs/carton, 36cartons/pallet
  • Delivery: 45 days
  • Customized black carriage bolts and nuts are available as per your samples or design.


What are carriage bolts?

Carriage bolts are round head square neck bolts, which also called cup head square neck bolts, including standard DIN 603 and ISO 8677.


Why is it called a carriage bolt?

As its name suggest, carriage bolts are first designed for the construction of carriages and their wheels.


What are carriage bolts used for?

A carriage bolt, also called coach bolt, cup head bolt, which are used to connect metal to metal or metal to wood by working with nuts and washers. Decorative carriage bolts and decorative coach bolts are most popular among Fastenwell's carriage bolts series.


What size are carriage bolts have?

Carriage bolt sizes chart as below, range from M5 to M20 in diameter, and larger diameter with longer length.

Carriage Bolt Sizes Chart


Screw Thread


M5 M6 M8 M10 M12 M16 M20
P Pitch 0.8 1 1.25 1.5 1.75 2 2.5
b L≦125 16 18 22 26 30 38 46
125<L≦200 22 24 28 32 36 44 52
L>200 / / 41 45 49 57 65
dk Max 13.55 16.55 20.65 24.65 30.65 38.8 46.8
Min 12.45 15.45 19.35 23.35 29.35 37.2 45.2
ds Max 5 6 8 10 12 16 20
Min 4.52 5.52 7.42 9.42 11.3 15.3 19.16
k1 Max 4.1 4.6 5.6 6.6 8.75 12.9 15.9
Min 2.9 3.4 4.4 5.4 7.25 11.1 14.1
k Max 3.3 3.88 4.88 5.38 6.95 8.95 11.05
Min 2.7 3.12 4.12 4.62 6.05 8.05 9.95
r1 10.7 12.6 16 19.2 24.1 29.3 33.9
r2 Max 0.5 0.5 0.5 0.5 1 1 1
r3 Max 0.75 0.9 1.2 1.5 1.8 2.4 3
s Max 5.48 6.48 8.58 10.58 12.7 16.7 20.84
Min 4.52 5.52 7.42 9.4 11.3 15.3 19.16


Fastenwell manufacture, stock and supply metric black carriage bolts, galvanized carriage bolts, decorative carriage bolts, decorative carriage bolts etc. They are in different grades like grade 4.8 carriage bolts, grade 8 carriage bolts. For carriage bolts pdf datasheet, please contact us now by


Do carriage bolts need nuts and washers?

Yes, carriage bolts and nuts can be used together, as well as a washers. Usually it will be hex nuts, lock nuts are not recommended.


Is a carriage bolt stronger than a hex bolt?

Yes, hex bolts with a washers with bigger bearing surface than that of a carriage bolts.


What's the different of carriage bolts and coach bolts?

Carriage bolts, also called coach bolts, if there will be any difference, it just exist in letters.


Are carriage bolts used for decks?

Yes, carriage bolts and cup head bolts are widely used for decks, as well as for metal and wood.


How do you attach carriage bolts to wood?

For carriage bolts in wood, firstly we have to drill a hole into the wood for the appropriate size and diameter of the bolt. Secondly we just slide the bolt into the hole with a hammer if in need. Lastly we can fasten it with a nut and washer.


How do you use carriage bolts in steel?

Put the carriage bolts into the steel parts and fasten them with a washer and nut by wrench. The adhesive will hold the nut in place long enough to get the bolt tight and the shoulders of the carriage bolt will dig into the metal and hold it as well.


How to use or install carriage bolts?

First you have to drill a hole and put the carriage bolts into the holes, then turn it tight with a nut and washer by wrench.


How to remove carriage bolts?

Get the nut back off to the end of bolt, then hit the nut with a hammer to moving the carriage bolt out of the wood.


Hot selling black carriage bolts, Galvanized carriage bolts

Fastenwell bolts range including Carriage bolts, Coach bolts, Heavy hex structural bolts, Hex cap boltshex flange bolts, hex socket head cap bolts, machine bolts etc.

If you couldnot find the bolts you want in our page, please send picture or drawing to our sales representives.



1. Are you a carriage bolts manufacturer?

Yes, we are metric carriage bolts supplier and manufacturer. 


2. How long is your delivery time for black carriage bolts?

It takes 7-10 days for stock products. For bulk order, it will be in 30-60 days according to the order quantity.


3. Can we have samples for galvanized carriage bolts?

Yes, free samples are available, if you have a courier acount like DHL/FEDEX/UPS to collect the samples.


4. Can we use our own head mark or customize package for dimension m12 carriage bolt?

Yes, customize headmark and package are acceptable, please send the requirements when place order.


5. How can we make an order for carriage bolts?

You can send us inquiry from the contact page or contact us at, we will check and revert quickly.

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