Knowing how to draw out metal is what separates banging on a bar from forging one. You heat the steel, strike it so it gets thinner and longer instead of just flatter, and turn it so it stays the shape you want. Drawing out steel is the move behind tapers, points, hooks, handles and the stock for nearly every beginner project, and it is the first thing I teach in a weekend class. This guide covers what the hammer does to the bar, the heat you need, how to draw out a bar from one end to the other, and how to take stock from square to octagon to round. It is owner-to-owner advice from a hobby smith, not a trade manual, so use it alongside in-person help if you can get it. If you are brand new, the Getting started hub lays out the order I would learn things in.
What drawing out does to a bar
Steel does not compress under the hammer. The volume of the bar stays about the same, minus a little lost to scale, so when you reduce the cross-section the metal has to go somewhere, and the only place left is length or width. Drawing out is the craft of persuading it to go into length.
The arithmetic is worth keeping in your head. Take a bar half an inch square and draw it to a quarter inch square. The cross-section area falls from a quarter of a square inch to one sixteenth, which is a quarter of what it was. The bar ends up roughly four times as long, a bit less once you count the steel that flaked off as scale. A 4-inch hot section becomes something near 16 inches. That is also why a long taper takes more heats than a beginner expects.
Which way the metal moves depends on the hammer face and how the bar sits. A wide, flat face on a thin bar squeezes metal sideways as readily as it pushes it along, so the bar spreads. A narrow face, like the peen of a cross peen hammer or the curve of the horn, drives the metal along the length. Most of the skill is knowing when you want spread and when you do not.
Drawing out has a few names. Some smiths say "drawing down" or "fullering and drawing" for slightly different jobs, and the opposite move, making a bar shorter and thicker, is upsetting. The blacksmithing terms glossary sorts out the vocabulary if a forum thread loses you.
Heat and steel before the first blow
Hot steel moves and cold steel resists, then cracks. For mild steel, the common owner advice is to work in the bright orange to yellow range and to stop when the bar fades to a dull red. At that point reheat. Hammering a bar at a dull red or darker is a common way to get surface cracks, and higher-carbon steels are less forgiving than mild steel. I leave forging temperature numbers for specific alloys out of this guide. Check the supplier's data sheet for the steel you actually bought, and for the science behind heat ranges, Knife Steel Nerds is the source I send people to.
Two heating habits matter more than any hammer technique:
- Heat the bar all the way through. A bar that is bright on the outside and dark in the core moves unevenly, and the hammer only works the skin. Let the color equalize before you pull it.
- Watch for burning. If a bar throws bright, branching sparks in the fire like a sparkler, the steel is burning, and burned steel turns crumbly and weak. Pull it out, cut off the ruined section and start again with good metal.
Both of my forges can do this work. The propane forge gives fast, even heat and handles most of my daily drawing out. The coal forge earns its keep on heavy stock. If you are choosing between them, coal or propane covers the tradeoffs.
Know what you are heating. Never forge galvanized steel; the zinc coating gives off fumes that can make you sick, and forging galvanized steel explains why. Unknown scrap is a different problem. You cannot know how it will behave, and mystery steel covers what to do with it. For learning, buy new mild steel bar from a steel supplier.
Setting up the anvil, hammer and tongs
Anvil height and position
Stand at the anvil with your arm hanging straight. The common rule, which I use, is that the face should sit about at your knuckles. Too high and your shoulder pays for it, and too low and your back does. Bessie, my 148 lb Trenton, sits on a stand cut to that height. The anvil stand article covers options, and the blacksmith anvil guide helps if you do not have an anvil yet.
Strike over the body of the anvil, where the steel face is backed by the mass underneath. Hammering over a thin overhang makes the bar bounce and wastes your blows.
The hammer
Most teachers start people on a medium hammer, and the range I hear and use is about two to three pounds. That is owner consensus, not a rule. The right hammer is one you can swing accurately for an hour. A cross peen hammer is the classic draw-out tool, and the blacksmith hammer page covers face shapes and weights in more depth.
The tongs
Tongs have to fit the bar. Loose jaws let the bar twist in your hand on every blow, and that rotation ruins your section. Choose jaws that close flat against the stock, and see blacksmith tongs if yours slip. Grip the reins firmly but let your wrist stay loose, because the hammer will send a jolt up the bar.
Drawing out a bar one step at a time
Here is the routine for drawing out a bar, assuming a half-inch square mild steel bar and a goal of a thinner, longer end.
- Heat the bar evenly, a few inches longer than the section you plan to draw.
- Lay the bar flat on the anvil face. Keep the hot section over the body of the anvil, with the cool end held in your tongs.
- Start at the end you want thinner, not in the middle. Strike with the hammer face parallel to the anvil face, so the blow lands flat instead of on an edge.
- Overlap your blows. Work from the tip back toward the thick stock, sliding the bar a little between strikes.
- Turn the bar a quarter turn after a blow or two. Hit, turn, hit, turn. That rhythm keeps the section square and keeps it from spreading into a flat strip.
- Check the section by eye or with calipers as you go. Stop when the color fades and reheat.
Hard blows early, light blows late
Heavy blows while the steel is bright move the whole cross-section. Light taps mainly work the surface, so the skin stretches while the core stays thick, and the bar can bulge in the middle. Use your best blows while the bar is hot and save light, controlled blows for the finishing pass.
Using the cross peen and the horn
Lay the bar across the horn, or turn the hammer so the peen runs across the bar, and the same blow drives more metal along the length. A curved surface concentrates force, so the horn can lengthen a bar quickly. It also leaves ridges and a slightly curved bar. Go back to the flat face with flat hammer blows to clean up. The hammer and anvil must always meet steel. Never swing the hammer onto the bare anvil face, because hardened steel on hardened steel can chip and throw pieces.
Square, octagon and round
Moving from square to octagon to round is the standard way to make a clean round. Hammering a round bar straight down tends to flatten it into an oval, and it fights you. Going through square gives you a shape you can control.
Forge the square first
Draw the bar to a square close to your final diameter. Aim at the finished round's size, not much larger. Keep turning between blows, and measure all four faces. A true square gives you the best start.
Knock the corners to make an octagon
Stand the bar on one corner, so the hammer face lies across that corner at about 45 degrees to the faces. Strike so the corner flattens into a new face. Turn the bar to the next corner and repeat. You end up with eight faces, and the four new ones should be about as wide as the four originals. If some faces are wider than others, you have an uneven octagon, and it will give you an out-of-round bar later.
Round it off
Now knock the eight corners lightly and keep the bar rotating almost constantly. Work with light, quick blows, rolling the bar between them, and check it by eye as you go. A bottom swage held in the hardy hole finishes the job faster and more evenly, and blacksmith swage explains how they work. Finish while the bar still has color. A cold bar finished with heavy hammer blows can crack or pick up bruises.
Drawing a taper
A taper is just drawing out with unequal effort: more reduction at the tip, less behind it. Taper to a square point first, then work the corners to octagon and round if you want a round point.
Keep the tip in line with the bar. If it hangs in the air or you strike on only one side, the point will curl and the tip will flatten into a sliver. Hold the bar level, hit the tip hardest, turn after each blow and let the cone develop gradually. Reheat before the tip goes dull. Thin tips lose heat fast, and the end is where the first cracks show up.
Mistakes that crack, fold or waste heats
- Working too cold. The surface cracks, and the damage may be invisible until later. When the color is gone, put the bar back in the fire.
- Hitting one side too many times. The bar spreads wide and flat. Turn more often.
- A diamond section. If the square leans into a rhombus, the hammer face was not parallel or the turns were off. The usual fix is to stand the bar on its sharp corner and strike down the long diagonal, which squares it. A teacher in person will show you faster than I can write it.
- Laps and cold shuts. If you hammer with the edge of the hammer, or let a thin edge fold over, you trap a seam in the steel. Forging over it only buries the seam. Cut the section off, or grind out a shallow flaw before you keep working, with a face shield on.
- Scale pressed into the surface. Brush the bar with a wire brush between heats. Scale flakes can fly off when you strike, so wear your eye protection for this step too.
- Heating a short section too often. Every heat costs steel to scale. Plan your blows so you make the most of each heat instead of reheating for two light taps.
Safety at the anvil
Hot scale, hot offcuts and flying chips are the everyday hazards. Wear safety glasses rated to ANSI Z87.1 every time you swing a hammer, with a face shield at the grinder. Early on I quenched a blade in oil that was too cold, in a cotton shirt with no face shield, and the flare-up took my eyebrows. I kept my eyesight by luck. Natural fibers like cotton and wool are better than synthetics near heat, since synthetic cloth melts onto skin. Wear closed leather boots, and tie back long hair.
A dark bar can still burn you. Steel loses its glow long before it is safe to touch, so assume anything that has been in the fire is hot and keep offcuts in one designated spot, away from where people walk. Forging is loud, and repeated hammering on steel will add up over the years, so see hearing protection for blacksmithing. The full list of what to wear is in blacksmith safety gear.
If you run a gas forge or any fuel-burning forge indoors, ventilate the shop and use a listed carbon monoxide detector. Flame color and smell are not reliable signals. Any symptom means you leave the shop and get medical advice. The forge carbon monoxide article goes into detail.
Finally, treat your own body as part of the setup. If your wrist, elbow or shoulder starts to ache, put the hammer down, shorten the session and look at your anvil height and hammer weight. None of this is medical advice, and anything that persists should be seen by a doctor.
Practice stock and where to go next
Buy a few feet of half-inch square or round mild steel bar and a few more of three-eighths. Use them for drills, not projects:
- Draw 3 inches of a half-inch bar to a quarter-inch square, keeping all four faces flat.
- Take that square to an octagon, then a round.
- Draw a four-sided taper to a point, then round it.
- Repeat on a bar you start round, and note how much more it fights you.
Cut each practice piece off and look at the section. Bar that looks good outside but is wrong in the cross-section is common, and an ugly drill piece teaches more than a pretty one. Once the drills feel steady, beginner blacksmith projects gives you things worth making with those skills. The beginner blacksmith guide covers the rest of the setup, and the Getting started hub collects every first-year article in one place.