EVERHARDLong Cut Insulation Knife with 3-5/8" long blade MK46000

This makes cutting insulation a breeze. Get yourself some cut proof gloves. It is sharp.

This is the best darn knife you could use for cutting insulation. It has a chisel end and both sides (all three sides) are sharpened--can't say how long that they will stay sharp but for the price buy another. I bought two and did my attic with one and it is still sharp. I lay a 2x2 on top of a bat of insulation as a guide, press it down to squash the fiber and zip zap it went thru the R30 un-faced insulation with one slice when cutting on top of a piece of plywood. I found that with faced insulation it was not quite as good and took two cuts. I liked the chisel pointed end as I used the corner to tear open the packaging easily. No sheath is provided to protect oneself from injury when you were not using it so a little care in that area for your own safety will be required. Blade was fairly stiff like a putty knife - I tried two other brand of knives that had more flexible blades that I did not care for - just for that reason. Wear gloves (which you should be using anyway) when working with fiberglass..

Excellent tool. I’m glad I wasn’t discouraged by negative reviews. Made 45 clean cuts today with this knife on 1 inch foam board. My set-up was two sawhorses with a sacrificial board beneath. Really happy I bought this. Did not dull and when it does eventually, I’ll just sharpen it with a filer.

I ordered this gloves to protect my hands from the fiberglass I'm working with. They pretty helpful and strong, easy to put on, or to take them off.

I do commercial roofing and this knife is a necessity for cutting insulation boards. Double sided edges make it simple to cut no matter what angle or limited space you have to operate in. Very durable I replace mine about once a year but not due to knife wearing out, because of the chemicals and glues like oli bond and primers I get on it. Keeping it sharp with a knife sharpener and it slices through up to 3" iso effortlessly.