Rail Joint Bolts / Fish Bolts
| Standard | EN 13481 ref · AREMA / UIC · OEM |
|---|---|
| Material | 45 Steel / 40Cr / 35CrMo |
| Strength Grade | 8.8 / 10.9 |
| Size Range | M16-M30 / 5/8-1 in |
| Surface Treatment | HDG / Black Oxide / Zinc Flake |
01
Product Description
Product Description & Key Specifications
Rail joint bolts, also called fish bolts, are supplied for railway fishplate and joint bar assemblies where the bolt must clamp rail joint components under vibration, impact and outdoor exposure. Material options include 45 Steel, 40Cr and 35CrMo with 8.8 / 10.9 grade references.
Fish bolt geometry is usually project-specific because head shape, neck design, thread length, shank diameter and nut compatibility must fit the rail joint bar system. AREMA, UIC and EN 13481 references help define the application, but drawings or samples are normally required for accurate production.
HDG finish is selected for outdoor corrosion protection, zinc flake can support improved corrosion resistance with controlled coating thickness, and black oxide is used where the project allows lower corrosion protection or specific assembly behavior. Locking method and washer selection should follow the track maintenance standard.
| Product type | Rail joint bolts / fish bolts |
|---|---|
| Standards | AREMA / UIC / EN 13481 reference / OEM drawing |
| Material | 45 Steel / 40Cr / 35CrMo |
| Strength grade | 8.8 / 10.9 |
| Size range | M16-M30 / 5/8-1 in |
| Common models | M20 x 90, M22 x 100, M24 x 110, M27 x 130, 7/8 x 4 in |
| Head / shank | Fish bolt head, neck and thread length by rail joint drawing |
| Surface finish | Hot-dip galvanized / Black oxide / Zinc flake |
| Documentation | MTC, CoC, dimensional report and coating report on request |
02
Selection
Selection Advantages by Application
Rail Fishplate Connections
M22, M24 and M27 fish bolts are common for fishplate and joint bar assemblies. Confirm rail section, fishplate hole pattern, bolt head form and nut/washer requirements.
Railway fastenersTrack Maintenance & Replacement
Replacement fish bolts should match existing rail joint hardware. Head geometry, thread length and shank fit are more important than diameter alone, so drawings or samples are useful.
Track maintenance fastenersHeavy Rail / Transit Infrastructure
35CrMo 10.9 rail joint bolts with zinc flake or HDG finish can be specified for higher-duty rail infrastructure where corrosion resistance and mechanical strength both matter.
Rail infrastructure fasteners03
Assembly
Recommended Matching Products
04
Manufacturing
Manufacturing & Quality Control
Manufacturing CapabilityQuality Control
Hot forging selected by fish bolt head and shank geometryIncoming 45 Steel / 40Cr / 35CrMo material verification
Thread rolling and special neck/head forming by drawingThread gauge, shank diameter, head form and overall length inspection
HDG, black oxide or zinc flake coatingCoating thickness, adhesion and visual coverage checks when specified
OEM rail joint bolt production from drawing or sampleTensile, hardness and dimensional reports arranged by project requirement
Nut/washer set packaging and track maintenance kitsMTC, CoC and inspection report prepared on request
05
FAQ
Common Questions Before RFQ
Why are rail joint bolts also called fish bolts?
They are used with fishplates or joint bars at rail joints, so the terms rail joint bolts and fish bolts often refer to the same product category.
What information is needed for fish bolt production?
Confirm rail section, fishplate drawing, diameter, length, head form, shank/neck geometry, thread length, material, grade, finish and matching nut/washer requirements.
Should I choose 8.8 or 10.9 grade fish bolts?
Grade selection depends on rail joint design, preload requirement and maintenance standard. 10.9 is used for higher-strength applications when approved by the project specification.
What sizes are commonly requested?
Common RFQ models include M20 x 90, M22 x 100, M24 x 110, M27 x 130 and inch sizes such as 7/8 x 4 in. Final geometry should follow the rail joint drawing.
Can fish bolts be supplied with HDG or zinc flake finish?
Yes. HDG, black oxide and zinc flake finishes can be supplied according to corrosion requirement, coating thickness limit and project standard.
Need rail joint bolts or fish bolts?
Send your rail joint drawing, size, grade, material, finish, head geometry, nut/washer requirement and test documents. Our team can confirm fish bolt production for railway maintenance or infrastructure projects.
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