8C-8580 Socket Head Bolt: Is an M5 x 16 Substitute Enough?
2026/09/27
Published by GUANGZHOU JIAJUE MACHINERY EQUIPMENT CO.,LTD
Purchasing guide | 27 September 2026
A substitute labelled “M5 x 16” leaves several purchasing questions unanswered. The 8C-8580 socket head bolt listing provides useful exterior views, while Caterpillar's published 493-4485 kit contents identify 8C-8580 as an M5-0.8 x 16 mm hex socket head bolt. That reference establishes nominal thread and length information; it does not prove that any look-alike fastener is suitable for the same joint.
Source: Caterpillar Parts Store, 493-4485 kit component listing. The kit is used here to verify the reference description, not to claim that it is the correct repair kit for your equipment.
Read the thread designation completely
In M5-0.8, M5 is the nominal metric thread diameter and 0.8 mm is the pitch. For this conventional socket-head form, confirm the specified length from the underside of the head to the end, rather than including the head height. Ask the supplier for a measured drawing when a quotation omits the measurement convention.
Keep diameter, pitch, length and head form in separate enquiry fields. Also check the required threaded length, head diameter and head height where recesses or nearby components limit space. A bolt can enter a hole yet still have insufficient engagement or interfere with the bottom of a blind hole.
Confirm the required fastener specification
Ask for the applicable strength class, material, finish and any locking requirement from the equipment's parts or service information. Black surface colour is not evidence of a particular grade or coating. A seller's generic “high strength” claim is not a substitute for a specification tied to the offered fastener.
Do not publish or use a universal tightening torque based only on M5 diameter. The joint design, fastener properties, surface condition and prescribed installation method matter. Have the technician use the exact service information, including any requirements for lubrication, locking product or replacement after removal.
| Option and inspection condition | Parts cost scope | Workshop time | Downtime and delivery considerations |
|---|---|---|---|
| Order the specified reference when the mating thread and joint remain serviceable. | Correct fastener plus any specified associated items. | Joint inspection and installation to the prescribed method. | Confirm quantity per joint and total quantity before dispatch. |
| Consider an alternative only after the complete fastener and joint requirements are matched. | Documented substitute and any approved associated items. | Additional specification review before installation. | A locally available bolt is not a time saving until suitability is established. |
| Repair a damaged mating thread or joint before installing a replacement fastener. | Approved repair or replacement components plus the required fastener. | Additional workshop work and verification. | A longer or larger bolt is not an automatic repair; schedule the approved corrective work. |
Write a quotation that can be checked
Provide the machine and assembly reference, fastener position in the parts diagram, required quantity and the full specification. Request traceable packaging and documentation if your maintenance process requires them. The photographs do not prove dimensional inspection or mechanical testing.
Illustrative comparison: Offer A states M5 x 16; Offer B also confirms pitch, head form and the required strength specification. Ask Offer A to complete those fields before comparing equal scopes. Include inspection, installation labour and the cost of waiting for the correct fastener, without inventing a universal saving.
Request a clearly scoped quotation
Send the identification details and inspection findings above to GUANGZHOU JIAJUE MACHINERY EQUIPMENT CO.,LTD, together with quantity and destination. Ask us to state the exact supplied components, supporting identification evidence and confirmed dispatch terms in the quotation.
These are purchasing checks, not a machine-specific repair procedure or a record of a completed customer repair. Product photographs show visible features; they do not establish internal condition, test performance or compatibility. Installation and testing should follow the applicable equipment service information.
