Index: lathe.lua
==================================================================
--- lathe.lua
+++ lathe.lua
@@ -31,17 +31,20 @@
 	local inv = minetest.get_meta(pos):get_inventory()
 	local tool = inv:get_stack('tool',1)
 	local tech = sorcery.lathe.tooltech(tool)
 	if not tech then return nil end
 	local wkpc = inv:get_stack('workpiece',1)
+	howmany = howmany or wkpc:get_count()
 	local rec = R[wkpc:get_name()][tech][idx]
 	local outn = ItemStack(rec.output):get_count()
-	local q = howmany / outn
+	local ntimes = math.floor(howmany / (rec.mass or 1))
 	return {
 		tool = tool, wkpc = wkpc;
-		cost = rec.cost * q;
-		qty = q, outn = outn;
+		cost = rec.cost * ntimes;
+		ntimes = ntimes;
+		tqty = math.floor(howmany / outn), outn = outn;
+		gqty = ntimes * outn;
 		tech = tech;
 		rec = rec;
 		inv = inv;
 	}
 end
@@ -63,32 +66,33 @@
 	local wmat = sorcery.itemclass.get(wkpc:get_name(),'material')
 	-- obey level restrictions. TODO honor Rend
 	if (wmat and wmat.data.level or 0) > (tmat and (tmat.data.maxlevel or tmat.data.level) or 0) then
 		return
 	end
-
+	
 	local tech = sorcery.lathe.tooltech(tool)
 	local rec = R[wkpc:get_name()][tech]
 	tech = sorcery.lathe.techs[tech]
 
 	-- fill in the preview slots
 	local j = 1
-	for i=1, inv:get_size('preview') do
-		local stk
-		if rec[i] and minetest.registered_items[ItemStack(rec[i].output):get_name()] then
-			local max = wkpc:get_count()
+	for i=1, inv:get_size 'preview'  do
+		local stk = ItemStack()
+		if rec[i] and minetest.registered_items[ItemStack(rec[i].output):get_name()] and (rec[i].mass == nil or rec[i].mass <= wkpc:get_count()) then
+			local l = sorcery.lathe.get(pos, i, wkpc:get_count())
+			local max = l.ntimes --math.floor(wkpc:get_count() / (rec[i].mass or 1))
 			if tech.dmg then
 				-- TODO count remaining tool uses
 			elseif tech.consume then
 				max = math.min(max, tool:get_count())
 			end
 			if max > 0 then
 				stk = ItemStack(rec[i].output)
 				stk:set_count(stk:get_count() * max)
-				inv:set_stack('preview',i,stk)
 			end
 		end
+		inv:set_stack('preview',i,stk)
 		j = j + 1
 	end
 
 	-- make sure remaining slots are clear
 	for i = j, inv:get_size('preview') do
@@ -184,15 +188,18 @@
 					local dur = mat.data.durability or dur
 					lfac = (mmat and mmat.data.level or 1) /
 						(mat.data.maxlevel or mat.data.level or 1)
 				end
 				local ch = 65535 / dur
-				l.tool:add_wear(4 * ch * l.cost * lfac)
+				l.tool:add_wear(ch * l.cost * lfac)
 			end
-			l.wkpc:take_item(l.qty)
+			l.wkpc:take_item(l.tqty)
 			l.inv:set_stack('tool', 1, l.tool)
 			l.inv:set_stack('workpiece', 1, l.wkpc)
+			if l.rec.leftover then
+				sorcery.lib.node.insert(ItemStack(l.rec.leftover), 'workpiece', pos, user, l.inv)
+			end
 			minetest.sound_play('sorcery_clank', { pos = pos, gain = 0.9 })
 		end
 		sorcery.lathe.update(pos)
 	end;
 

Index: metal.lua
==================================================================
--- metal.lua
+++ metal.lua
@@ -46,16 +46,18 @@
 	local ingot = metal.ingot or 'sorcery:' .. name .. '_ingot'
 	local block = metal.block or 'sorcery:' .. name .. 'block'
 	local screw = 'sorcery:screw_' .. name
 	local fragment = 'sorcery:fragment_' .. name
 	local powder = 'sorcery:powder_' .. name
+	local disc = 'sorcery:disc_' .. name
 	metal.parts = {
 		ingot = ingot;
 		block = block;
 		screw = screw;
 		fragment = fragment;
 		powder = powder;
+		disc = disc;
 	}
 	if not metal.no_tools then for t,c in pairs(tools) do
 		sorcery.matreg.lookup[(metal.items and metal.items[t]) or ('sorcery:' .. t .. '_' .. name)] = {
 			metal = true;
 			id = name; data = metal;
@@ -82,24 +84,34 @@
 		value = 1;
 	}
 	minetest.register_craftitem(screw, {
 		description = sorcery.lib.str.capitalize(name) .. ' Screw';
 		inventory_image = sorcery.lib.image('sorcery_screw.png'):multiply(sorcery.lib.color(metal.tone)):render();
-		groups = {
-			metal = 1;
-			sorcery_screw = 1;
-			sorcery_tech_component = 1;
-		};
+		groups = { metal = 1; sorcery_screw = 1; sorcery_tech_component = 1; };
 		_sorcery = {
 			material = {
 				id = name, data = metal;
 				powder = powder;
 				grindcost = 2, grindvalue = 1;
 				value = 0.5;
 			};
 		};
 	})
+	minetest.register_craftitem(disc, {
+		description = sorcery.lib.str.capitalize(name) .. ' Disc';
+		inventory_image = sorcery.lib.image('sorcery_disc.png'):multiply(sorcery.lib.color(metal.tone)):render();
+		groups = { metal = 1; sorcery_disc = 1; sorcery_tech_component = 1; };
+		_sorcery = {
+			material = {
+				id = name, data = metal;
+				powder = powder;
+				grindvalue = (3*4) / 2;
+				value = 4 * (2/3);
+			};
+		};
+	})
+
 	local reglathe = function(ty, sz)
 		sorcery.lathe.register {
 			input = ty;
 			output = {name = screw, count = sz * 2};
 			tech = 'cut', cost = 1;
@@ -106,10 +118,23 @@
 		}
 	end
 	reglathe(fragment, 1)
 	reglathe(ingot, 4)
 	reglathe(block, 4 * 9)
+
+	sorcery.lathe.register {
+		input = ingot, mass = 2;
+		output = {name = disc, count = 3};
+		tech = 'cut', cost = 5;
+	}
+	sorcery.lathe.register {
+		input = block;
+		output = {name = disc, count = 8*3};
+		leftover = ingot;
+		tech = 'cut', cost = 5*7;
+	}
+
 	minetest.register_craftitem(powder, {
 		description = sorcery.lib.str.capitalize(name) .. ' Powder';
 		inventory_image = 'sorcery_' .. name .. '_powder.png';
 	})
 	if metal.dye then

Index: recipes.lua
==================================================================
--- recipes.lua
+++ recipes.lua
@@ -370,15 +370,17 @@
 regtech('valve','Valve', {metal = 1}, {
 	{'','default:bronze_ingot',''};
 	{'basic_materials:plastic_sheet','basic_materials:steel_bar','basic_materials:plastic_sheet'};
 	{'','default:bronze_ingot',''};
 },3,nil, mprop('bronze',2*4,1,2*4))
-regtech('pipe','Pipe', {metal = 1}, {
-	{ingot('aluminum'),'',ingot('aluminum')};
-	{ingot('aluminum'),'',ingot('aluminum')};
-	{ingot('aluminum'),'',ingot('aluminum')};
-}, 6, nil, mprop('aluminum', 4))
+regtech('pipe','Pipe', {metal = 1},nil, nil, nil, mprop('aluminum', 4))
+
+sorcery.lathe.register {
+	input = ingot('aluminum');
+	output = 'sorcery:pipe';
+	tech = 'cut', cost = 8;
+}
 
 minetest.register_craft {
 	output = 'sorcery:trough';
 	recipe = {
 		{ingot('aluminum'),'',ingot('aluminum')};
@@ -791,8 +793,17 @@
 end
 
 sorcery.lathe.register {
 	output = 'basic_materials:steel_bar 2';
 	input = 'default:steel_ingot';
-	tech = 'cut';
-	cost = 3;
+	tech = 'cut', cost = 3;
+}
+sorcery.lathe.register {
+	output = 'basic_materials:steel_bar 18';
+	input = 'default:steelblock';
+	tech = 'cut', cost = 3*9;
+}
+sorcery.lathe.register {
+	output = 'basic_materials:steel_bar';
+	input = 'default:steel_fragment', mass = 2;
+	tech = 'cut', cost = 2;
 }