It's a fiber board, cheaper than plywood and has been replaced with OSB now. It was used on walls and roofs. I would think it would hold nails fine but you could do a pull out test of sorts your self. It wasn't made with asbestos but made in the same plant and same machines as the old asbestos cement board and there could be a little cross contamination but that would be little at best.
Vintage Sheathing
Anyone know the history of this product or what it is made of? Tearing off vinal siding and what appears to be old wood siding and wondering if this has good nail holding properties. Seems to but never seen this before. House was built in 1965
