Armor rework (#5158)

Co-authored-by: silicons <no@you.cat>

code/modules/materials/material_sheets.dm

@@ -1,7 +1,7 @@
 // Stacked resources. They use a material datum for a lot of inherited values.
 // If you're adding something here, make sure to add it to fifty_spawner_mats.dm as well
 /obj/item/stack/material
-	force = 5
+	damage_force = 5
 	throw_force = 5
 	w_class = ITEMSIZE_NORMAL
 	throw_speed = 3
@@ -368,10 +368,10 @@
 	plank_type = /obj/item/stack/material/wood/hard
 
 /obj/item/stack/material/log/attackby(var/obj/item/W, var/mob/user)
-	if(!istype(W) || W.force <= 0)
+	if(!istype(W) || W.damage_force <= 0)
 		return ..()
 	if(W.sharp && W.edge)
-		var/time = (3 SECONDS / max(W.force / 10, 1)) * W.tool_speed
+		var/time = (3 SECONDS / max(W.damage_force / 10, 1)) * W.tool_speed
 		user.setClickCooldown(time)
 		if(do_after(user, time, src) && use(1))
 			to_chat(user, "<span class='notice'>You cut up a log into planks.</span>")