Air dry is softer than heat cure.Air dry is about an H-6 on the Graphite pencil scratch scale,Teflons and KG are about an H-3 to H-4.Oven cure is an H-7 or 8 comming out of the oven and will final cure to an H-9 within 5 days.The air dry is for high heat applications and will go into flux and get harder at about 750 degrees.It's used on automatic weapons bbls.and suppressors.
