A carbon-carbon screw that gallings or loosens under heat stops the assembly it holds. Carbon-carbon screws keep threaded joints strong in hot zones, but only when the specs are right. This article covers five specs that stop galling in service.
Jiecheng Graphite (since 2003) machines carbon-carbon screws to spec, and confirms thread and grade in writing.
Five specs that stop galling
Thread form decides engagement and strength. Grade sets temperature and load. Clearance allows for expansion. Finish controls friction and seizing. And torque must match the joint, not overtighten.
· Thread form — correct pitch and engagement
· Grade — rated for temperature and load
· Clearance — room for expansion
· Finish — low friction, no seizing
· Torque — matched to the joint
Where carbon-carbon screws are used
Carbon-carbon screws fasten hot-zone assemblies where metal galling is a problem. Confirm the thread, temperature and load before ordering.
· Hot-zone fasteners and joints
· Furnace assembly screws
· High-heat structural joints
What to specify before you buy
Send the thread, temperature and load. Jiecheng Graphite machines carbon-carbon screws in its Dalang, Dongguan plant and ships worldwide.
Spec | What to confirm | Why it matters |
Thread | Pitch + fit | Sets strength |
Grade | Temp + load | Sets life |
Clearance | Gap | Stops seizing |
Finish | Ra value | Stops galling |
Torque | Value | Protects joint |
Buying checklist
1. Send thread, temperature and load
2. Confirm grade and clearance
3. Specify finish and torque
4. Agree inspection per batch
5. Freeze the screw spec
FAQ
Why does my screw seize?
Too little clearance or too much torque; adjust both.
What grade handles hot joints?
A carbon-carbon grade rated for the temperature and load.
How do I stop galling?
Confirm the finish and use the correct clearance and torque.
Stopping carbon-carbon galling
Galling in a carbon-carbon screw is preventable with the right specs. Confirm the thread, clearance and torque before the screw reaches a hot joint. Jiecheng Graphite machines carbon-carbon screws to the thread you specify and documents finish and clearance, so the joint holds.
· Confirm thread and clearance
· Set the recommended torque
· Document finish per batch
A carbon-carbon screw holds when thread, grade, clearance, finish and torque are right. Jiecheng Graphite has made carbon-carbon screws since 2003 and keeps the spec on file.
