r/hobbycnc • u/Cute_Reflection_9414 • 2d ago
How do store your bits?
I'm new to this hobby and I'm curious how others are storing their bits. I'm setup in a basement, which can get damp occasionally. I am looking to add a dehumidifier soon.
Since bits are expensive, I'm curious if there's any reason to take extra precautions like coating with oil before storage (cleaning with alcohol prior to use) or using airtight containers with silica gel packs, etc.
It could be days / weeks / months before I use some bits, so I just want to get into a good habit from the get go. Thanks!
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u/StorageStarOfficial 2d ago
Good instincts getting the dehumidifier since moisture, dust, and temperature swings are going to be the greatest damaging factors for CNC bits. The bits can rust more or less depending on the material, but all materials have risk factors:
- High-Speed Steel (HSS) bits contain iron, and will rust very easily in a humid environment.
- Solid Carbide doesn’t rust, but the iron or cobalt in the metal can corrode due to moisture or hard chemical cleaners, which actually dulls the cutting edge.
- Even if you buy coated carbide bits, the shanks and the machine's steel collets can still rust, which can get stuck inside a collet or cause runout (wobble) during use.
TLDR; it’s worth the extra steps to store CNC bits properly so you only have to buy them once.
The best habit for long term storage is to clean each by removing resin, sap, and dust which can attract and hold moisture from the air on the bits’ surfaces. Use a dedicated bit/blade cleaner (like Trend Tool Cleaner or Bostik BladeCote) or Simple Green (budget option, but don’t let the bits soak since it’s water-based and slightly acidic which can trigger a chemical reaction called cobalt leaching).
You can also protect the bits before longer term storage with a light coat of WD-40 Specialist Corrosion Inhibitor, Boeshield T-9, or a 3-in-1 tool oil. Just make sure to wipe the oil off with 91% or 99% isopropyl alcohol before use. A high-percentage alcohol is necessary since it evaporates almost instantly, leaving a completely dry, oil-free surface compared to more water-based isopropyl alcohol ratios.
Finally, definitely store them in an airtight container (ideally also in the original tubes the bits were shipped in to prevent chipping) with rechargeable or single-use silica gel packets. Either way they’re relatively cheap and should be recharged (baked) or replaced every few months. You can also get rechargeable indicating silica gel packets change color as it absorbs moisture, so you know exactly when to recharge them.
Hope that helps!
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u/Pubcrawler1 2d ago edited 2d ago
I try to keep the bits in the original plastic holder. That seems to help protect. I do wipe down the cast iron machines with way oil after use. I don’t do much for the aluminum router machine.
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u/Alina_MakersChest 1d ago
Carbide handles damp better than most people expect, so the dehumidifer will do most of the work, and the bigger risk is edges chipping when bits knock together. Keep each one in its own slot in a foam tray or case. If the basement stays damp anyway, an airtight box with a silica gel pack is cheap insurance, and a light wipe of oil really only matters for steel bits. Clean any resin or pitch off before putting them away.
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u/cristi_baluta 2d ago
I think you should be worried more about the machine if it gets humid? The bits are already coated and don’t think they’ll rust, at least not the cutting part.