Norway-Style Elevator Bolts
ASME B18.5 · ¼ – ⅜″A flat head with a square shoulder, the most common style in the US grain industry. The square shoulder grips a round belt hole so the bolt cannot spin.
Norway Bucket Elevator Bolts, ASME B18.5 & DIN 15237: Manufacturer & Distributor
An elevator bolt fixes a bucket to the belt of a bucket elevator. Its wide, thin head spreads the load so it does not pull through the belt. The flat head lies flush on the pulley side, and a square neck stops the bolt turning while the nut is tightened.
Exotic Alloy manufactures elevator bolts in Mumbai, India. Inch Norway-style bolts follow the ASME B18.5 elevator bolt dimensions, and metric belt bolts follow DIN 15237. Heads are cold forged from ductile low-carbon or stainless wire, and the square neck is formed in the same blow. We supply grain, cement, fertiliser and food plants and conveyor builders in India, and distribute to Australia, the Gulf, Africa and Southeast Asia.
Ready Stock, Quick Delivery
¼″, ⅕″ and ⅜″ zinc plated and stainless elevator bolts ship from stock in standard lengths, with nut and washer kits. DIN 15237 sizes, long lengths and special heads are made to order.
¼ – ⅜″ | M6 – M12
Flat head, square neck
Zinc plated or stainless
Nut & washer kits
Bulk packs for elevator builders
Elevator bolt at a glance
- Head
- Wide flat head, about 4 × d, with a shallow conical underside
- Neck
- Integral square neck that locks in the belt
- Standards
- ASME B18.5 (inch), DIN 15237 (metric)
- Material
- Low-carbon steel, zinc plated; SS 302 / 304 / 316
- Fitted with
- Hex nut, split lock washer, fender or flat washer
- Related
- Carriage bolts, countersunk bolts
Elevator Bolt Specification
The range we manufacture and supply.
StandardsASME B18.5 elevator bolts (inch); DIN 15237 seating screws for belts (metric); SAE J429 / ASTM F593 properties; DIN 555 and ASME B18.2.2 nuts
Size range¼″, ⅕″, ⅜″ in lengths 1″ to 4″; M6, M8, M10, M12 in lengths 20 to 70 mm; other sizes to drawing
ThreadUNC class 2A (inch); metric coarse 6g; rolled; minimum thread length 2D + ¼″ for B18.5 bolts
HeadWide flat head with a shallow conical underside and an integral square neck; plain or with a recessed mark
PropertiesLow-carbon steel, Rockwell B70–B100, proof 33 ksi, yield 36 ksi (SAE J429 Grade 1 level); Grade 2 or better on request
MaterialsAISI 1006–1050 low-carbon steel; stainless 302, 304, 316; other alloys to order
FinishZinc plated clear or yellow (ASTM F1941); plain; passivated stainless
HardwareHex nuts, split lock washers, fender washers (plastic buckets) and flat washers (metal buckets), in matching material and finish
CertificationMill certificate with heat number; dimensional and hardness report; PMI on stainless
PackingBoxes of 100 or bulk cartons; bolt, nut and washer kits per bucket count on request
Types of Elevator Bolts We Manufacture
DIN 15237 Belt Bolts
M6 – M12 · heads 20 – 42 mmThe metric bolt for fixing buckets and other parts to belts on continuous handling equipment, used with DIN 555 nuts and cupped washers.
Stainless Elevator Bolts
SS 302 · 304 · 316For food, sugar, salt, fertiliser and wet service, where zinc plating would corrode or contaminate the product. This is the type in the product photo.
Special Elevator Bolts
To drawingLarger heads, longer necks, finned or ribbed necks, metric square necks and heavy sizes for high-capacity elevators.
Elevator bolt, carriage bolt or countersunk bolt?
| Feature | Elevator bolt | Carriage bolt | Countersunk bolt |
|---|---|---|---|
| Head | Very wide, thin and flat | Round dome | Cone, flush in a countersink |
| Anti-rotation | Square neck | Square neck | None (needs a drive) |
| Best in | Belts, fabric, rubber, thin sheet | Timber | Machined steel parts |
| Flush surface | Yes, pulls into the belt cover | No, dome stands proud | Yes, in a machined countersink |
Elevator Bolt Dimensions: ASME B18.5 & DIN 15237
| Size | Threads / in | Body E max / min | Head A max / min, sharp edge | Head A min, flat edge | Head height H max / min | Square width O max / min | Square depth P max / min | Min. thread length 2D + ¼ |
|---|---|---|---|---|---|---|---|---|
| 1/4″ | 20 | 0.260 / 0.237 | 1.008 / 0.969 | 0.938 | 0.098 / 0.078 | 0.280 / 0.245 | 0.219 / 0.188 | 0.750 |
| 5/16″ | 18 | 0.324 / 0.298 | 1.227 / 1.188 | 1.157 | 0.114 / 0.094 | 0.342 / 0.307 | 0.250 / 0.219 | 0.875 |
| 3/8″ | 16 | 0.388 / 0.360 | 1.352 / 1.312 | 1.272 | 0.145 / 0.125 | 0.405 / 0.368 | 0.250 / 0.219 | 1.000 |
Dimensions in inches. Length is measured from the top of the head to the end of the bolt. Length tolerance: +0.02 / −0.03″ up to 1″; +0.02 / −0.04″ over 1″ to 2½″; +0.04 / −0.06″ over 2½″ to 4″.
| Thread d | Pitch P mm | Head dk mm | Head height k mm | dk / d | Nominal lengths mm | Nut |
|---|---|---|---|---|---|---|
| M6 | 1 | 20 | 2.5 | 3.3 | 20 to 70 | DIN 555 |
| M8 | 1.25 | 28 | 3.5 | 3.5 | 20 to 70 | DIN 555 |
| M10 | 1.5 | 35 | 4.5 | 3.5 | 20 to 70 | DIN 555 |
| M12 | 1.75 | 42 | 5.2 | 3.5 | 20 to 70 | DIN 555 |
DIN 15237 (1980), “seating screws and cupped washers for the attachment of components to belts”. Head diameter dk and height k as published; please send the bucket drawing for the neck form and thread length.
| Size | Head diameter in | Square shoulder height in | Max. torque ft·lb (N·m) | Lengths in |
|---|---|---|---|---|
| 1/4″ | 1″ | 7/32″ | 6 (8.1) | 1, 1-1/4, 1-1/2, 2 |
| 5/16″ | 1-3/16″ | 1/4″ | 13 (17.6) | 1 to 2-1/2 in 1/4 steps |
| 3/8″ | 1-1/4″ | 1/4″ | 23 (31.2) | 1 to 2 in 1/4 steps |
A leading US elevator component maker's published data for #1 Norway bolts, for reference. Its 3/8″ head (1-1/4″) is smaller than the B18.5 table above. The torques are maximum values; the installed torque depends on the bucket and belt.
Fitting Elevator Bolts to Buckets & Belts
The bolt goes in from the pulley side of the belt, so that the flat head runs on the pulleys and the nut sits inside the bucket.
Do
- Punch belt holes to the bucket maker's pattern and the bolt diameter
- Insert bolts from the pulley side, so heads face the pulleys
- Tighten evenly until the head is drawn flush into the belt cover
- Re-check nuts after the first hours of running and at each inspection
Don't
- Over-tighten: it crushes the belt or cracks plastic buckets
- Leave heads proud of the belt: they wear the pulley lagging
- Mix stainless bolts with zinc plated nuts in wet service
- Reuse bolts with damaged square necks: they will spin
Bucket & Elevator Bolt Quantity Planner
Estimate the belt length, the number of buckets and the bolts to order for a two-pulley bucket elevator.
Elevator details
Belt length L = 2C + π(D1 + D2)/2 + (D1 − D2)²/4C, ignoring the splice. Buckets = L / spacing, rounded down. Spares at 5 % is our suggestion.
Estimate
142
buckets
568
elevator bolts
Belt length:42.83 m
Order with 5 % spares:597
Max. torque (Norway, maker's data):13 ft·lb (17.6 N·m)
Elevator Bolt Grades & Finishes
Elevator bolts carry modest loads, so ductility comes before strength: the thin head must form without cracking and flex with the belt.
| Grade | Proof | Yield min | Tensile min | Hardness | Use |
|---|---|---|---|---|---|
| Low-carbon steel (SAE J429 Grade 1 level) | 33 ksi | 36 ksi | 60 ksi | B70–B100 | Standard elevator bolts |
| SAE J429 Grade 2 (¼–¾″) | 55 ksi | 57 ksi | 74 ksi | B80–B100 | Heavy-duty elevators, on request |
| Stainless 302 / 304 (F593 Group 1) | Per ASTM F593 condition (CW1: 100–150 ksi tensile, 65 ksi yield, ¼–⅝″) | – | Food, wet and corrosive service | ||
| Stainless 316 (F593 Group 2) | Per ASTM F593 condition | – | Salt, fertiliser and chemical plants | ||
| Finish | Specification | Notes |
|---|---|---|
| Zinc plated, clear | ASTM F1941 Fe/Zn 3AN or 5AN | The usual finish for grain elevators |
| Zinc plated, yellow | ASTM F1941 Fe/Zn 3C or 5C | Better salt-spray life than clear |
| Plain | Oiled | Dry indoor service only |
| Passivated stainless | ASTM A967 / A380 | 302, 304 and 316 bolts |
Elevator Bolt Materials
Every grade links to its datasheet on this site.
How Our Elevator Bolts Are Made
1
Annealed wire
Low-carbon or stainless wire with high ductility, since the head is upset to about four times the wire diameter.
2
Multi-blow heading
The head is spread in stages and the square neck is formed in the final die, without splitting the thin edge.
3
Thread rolling
UNC or metric threads rolled to at least the B18.5 minimum length.
4
Plating or passivation
Zinc plated to ASTM F1941, or stainless passivated.
5
Inspection & kitting
Head, neck and thread checked; nuts and washers matched and packed by bucket count.
Where Our Elevator Bolts Are Used
Grain & feed elevators
Bucket elevators in silos, grain terminals, rice and flour mills, and feed plants.
Cement & minerals
Belt bucket elevators for cement, lime, sand and aggregates.
Fertiliser & chemicals
Stainless 316 bolts where salts and moisture attack zinc.
Sugar & food processing
Stainless bolts on food-grade buckets and belts.
Conveyor belt attachments
Fixing cleats, sidewalls, scrapers and wear strips to belts.
Farm machinery
Combine harvester and seed handling elevators and conveyors.
Elevator Bolt Inspection & Certification
| Check | Method | Applied to |
|---|---|---|
| Head diameter & height | Callipers against B18.5 or DIN 15237 limits | Every lot |
| Head edge | Visual and magnified check for splits and laps | Every lot |
| Square neck | Width and depth against O and P | Every lot |
| Thread | Ring gauges after plating | Every lot |
| Hardness | Rockwell B | Every heat |
| Coating | Magnetic or XRF thickness | Plated lots |
Every shipment includes
- Mill certificate with heat number
- Dimensional and hardness report
- Coating thickness report
On request
- EN 10204 3.1 certificate
- PMI report for stainless
- Kitting by elevator and bucket count
Elevator Bolt Questions, Answered
An elevator bolt has a very wide, thin flat head with a shallow conical underside and a square neck. It fixes buckets to the belt of a bucket elevator: the large head spreads the load so the bolt does not pull through the belt, the flat head lies flush on the pulley side so it runs smoothly over the pulleys, and the square neck stops the bolt turning while the nut is tightened. The inch version is standardised in ASME B18.5.
Norway is the most common style of elevator bolt in the US grain industry: a flat head with a square shoulder under it. The square shoulder bites into a round hole in the belt so the bolt cannot spin while the nut is tightened. Norway bolts are usually 1/4, 5/16 or 3/8 inch, with heads about 1 to 1-1/4 inch across.
For a 5/16 inch elevator bolt, ASME B18.5 gives a head diameter of 1.188 to 1.227 inch, a head height of 0.094 to 0.114 inch and a square neck 0.307 to 0.342 inch wide and 0.219 to 0.250 inch deep. The 1/4 inch bolt has a 0.969 to 1.008 inch head and the 3/8 inch bolt a 1.312 to 1.352 inch head. Length is measured from the top of the head.
The bolt goes through the belt from the pulley side, then through the bucket. For plastic buckets the stack is a fender washer, a split lock washer and a hex nut; for metal buckets it is a flat washer, a split lock washer and a hex nut. One elevator component maker advises against nylon insert lock nuts on Norway bolts.
Tight enough to pull the head flush into the belt cover without crushing the belt or cracking a plastic bucket. One elevator component maker lists maximum torques of 6 ft-lb for 1/4 inch, 13 ft-lb for 5/16 inch and 23 ft-lb for 3/8 inch Norway bolts, and notes that the right torque depends on the bucket and belt. Re-check the nuts after the first hours of running.
DIN 15237 is the German standard for seating screws and cupped washers used to attach components, such as elevator buckets, to belts of continuous handling equipment. It covers M6 to M12 bolts with heads 20, 28, 35 and 42 mm across and 2.5 to 5.2 mm high, used with DIN 555 hex nuts.
Standard elevator bolts are low-carbon steel, AISI 1006 to 1050, with a core hardness of Rockwell B70 to B100, a proof stress of 33,000 psi and a yield of 36,000 psi minimum, which corresponds to SAE J429 Grade 1. Some makers supply Grade 2 or better. Stainless 302, 304 or 316 elevator bolts are used for food, fertiliser, salt and wet service.
Multiply the number of buckets by the bolts per bucket. The number of buckets is the belt length divided by the bucket spacing, and the belt length of a two-pulley elevator is about twice the centre distance plus half the sum of the pulley circumferences. Order some spares for maintenance. The planner on this page does the calculation.