WARRANTY AND MAINTENANCE
Warranty
All Extrema Ratio knives are covered by a lifetime warranty.
Sheaths are covered by a 2-year warranty from the date of first purchase.
The warranty covers defects in workmanship, treatments, or materials that affect functionality. In such cases, we repair when possible; if repair is not feasible, we replace the product with a new factory model.
If the issue is found not to be covered by the warranty, a repair quotation will be provided.
- damage resulting from normal wear and tear
- damage resulting from normal wear and tear
- damage caused by improper use, modifications, and/or processes that alter the original factory specifications of the product
Important: Any repair and/or modification not carried out by Extrema Ratio (including repairs, disassembly, modifications, or sharpening outside specifications) will void the warranty.
WARRANTY RETURNS / REPAIRS
Return the product directly to the store where it was purchased. The dealer will handle the return procedure and service request with Extrema Ratio.
- proof of purchase or payment showing the date of first purchase
- a detailed description of the issue
- clear and detailed photos
After verification, you will receive return authorization (RMA) and operating instructions.
Do not ship any product before receiving authorization.
- a copy of the RMA authorization
- a clear description of the issue and/or requested service
- a complete return address (we do not ship to PO Boxes)
Repair timelines, depending on the type of service required, will be communicated during the acceptance phase.>br>
Important: Products sent without an RMA code will not be accepted and will be returned at the sender’s expense.
MAINTENANCE AND CARE
Basic Rules
Keep the knife clean, dry, and lubricated.
Use specific synthetic lubricants (including firearm lubricants): apply sparingly, but correctly.
Depending on the environment
- Salt water: rinse with fresh water, dry thoroughly, lubricate. (Salt is the enemy.)
- Fresh water/mud: rinse, dry, lubricate.
- Grease and heavy dirt: use household detergent, then dry and lubricate.
- Sheath: keep the inside clean. Sand and abrasive debris can scratch the blade when you sheathe/unsheathe.
FIXED BLADE KNIVES
Handles, rigid sheaths, and straps are made from high-resistance materials.
Screws and metal components are designed to reduce oxidation.
The blade is the element requiring the most attention, even with surface coatings: coatings may wear with use.
This is normal. It means the knife is doing its job.
FOLDING KNIVES
The blade requires the most care, even when treated or coated.
We recommend cleaning and lubricating using swabs and brushes without disassembling the knife.
Frequent disassembly may compromise components and assembly quality.
KITCHEN KNIVES
When used correctly, they retain their edge for a long time.
Avoid impacting the edge against hard materials (metal, stone, glass).
Sharpening should only be performed by experienced or professional sharpeners.
Do not wash in a dishwasher. Use with maximum care.
EXTRAORDINARY MAINTENANCE
In case of wear or damage, it is often possible to replace individual components without replacing the entire product.
Components subject to wear can be replaced.
Heavily worn edges should be restored by the manufacturer or an authorized professional.
SHARPENING
Sharpen using natural stones or diamond plates, with quality tools and appropriate grits:
- Coarse grit for damage and major restoration;
- Fine grit for maintenance and finishing.
Basic rule: maintain correct geometry and work on the edge with controlled movements.
PRO FAQ — MAINTENANCE AND CARE
How often should I lubricate my knife?
What is the correct routine after use?
I used the knife in salt water—what should I do immediately?
1. Rinse with fresh water (immediately).
2. Dry thoroughly (including hidden areas).
3. Lubricate.
Remember: salt is aggressive and accelerates oxidation.
Can I disassemble a folding knife for deep cleaning?
Avoid disassembly. Clean and lubricate using swabs and brushes without taking it apart. Repeated disassembly can compromise components and assembly quality and may void the warranty.
What lubricant should I use, and how much?
The coating/treatment is wearing off—is this normal?
Yes. Surface coatings may wear with use. This is not a defect; it is a sign of use. Proper maintenance protects the blade and keeps it efficient.
My sheath is scratching the blade—why?
Almost always due to sand or abrasive debris inside the sheath. Clean the interior regularly and remove dirt and particles.
Sharpening: what rule prevents mistakes?
Maintain correct geometry.
Use coarse grit only for damage or major restoration; fine grit for maintenance and finishing.
Controlled motion, constant pressure.
When should I perform “extraordinary maintenance”?
When a component is worn or damaged. Often, a single part can be replaced without replacing the entire product. For heavily worn edges: restoration by the manufacturer or an authorized professional.
What should I do before storing the knife for a long time?
Clean, dry, and lightly lubricate it. Store it in a way that prevents trapped moisture and check it periodically.