Materials and steel
ANA-10What steel are handpans made from?#
beginner
Short answer. Almost all of them start life as a thin sheet of steel formed into a hemisphere. The two main families are low carbon deep drawing steel, most often DC04, which is then usually gas nitrided, and ferritic stainless steel, most often AISI 430 or a maker specific variant such as Ayasa’s Ember.The reason a specific grade matters is that the shell has to survive being deep drawn into a dome and then hammered for hours without cracking, while still being springy enough to hold a stable note afterwards. Deep drawing steels are designed for exactly the first half of that: they are low in carbon, very ductile and formable, and they draw into deep shapes without tearing. DC04 is the workhorse grade, part of the European EN 10130 family of cold rolled low carbon steels for cold forming. Some makers use the American equivalent territory, roughly AISI 1008.
PANArt described their own material, which they called Pang steel, as fine steel sheet whose soft ferric crystal matrix is infused with nitrogen at 580 degrees Celsius, forming hard nitride crystals and producing what they termed a high strength metal matrix composite. They were explicit about the properties they were chasing: high elasticity under hammer blows, strong restoring force so the sound does not distort, low internal damping, high modulus of elasticity and high tensile strength, and a surface that is pleasant to touch.
The stainless route is a different trade. Ferritic stainless such as 430 has enough chromium to resist corrosion without the nickel content of the more familiar austenitic grades, and crucially it stays magnetic and formable. It is harder to work and harder to tune, but it does not rust in normal use.
Raw or untreated DC04, with no nitriding at all, is used by some makers, usually finished with oil or a coating. It is the softest and easiest to tune, and by a wide margin the most rust prone.
Shells themselves may be bought in from specialist suppliers or drawn in house. Many small makers buy shells and do their own hammering, tuning and heat treatment.
ANA-11Nitrided, stainless or raw: what is the difference?#
beginner
Short answer. Raw is untreated low carbon steel: warm, easy to tune, rusts readily. Nitrided is that same steel case hardened in a nitrogen atmosphere: harder surface, crisper and more ceramic sound, much better rust resistance than raw but still not immune. Stainless is a chromium alloy that resists rust almost entirely and typically rings longer and brighter.These are three genuinely different materials, not three finishes on one material.
Raw steel is DC04 or similar with nothing done to the surface beyond perhaps oil or paint. It is soft, which makes it forgiving to hammer and quick to tune, and it gives a warm, slightly dark tone. It is also the version that will rust if you leave a fingerprint on it overnight in a humid room. Very few makers sell raw instruments as a mainstream product, and those that do usually treat them as budget or experimental builds.
Nitrided steel is the historical mainstream, going back to PANArt. The finished shell is heated in a nitrogen rich atmosphere so nitrogen diffuses into the surface and forms hard iron nitrides. The result is a hard, dark grey to blue black surface over a still ductile core. Sound is typically described as percussive, ceramic or gong like, with a defined attack and a decay that is shorter and cleaner than stainless. Rust resistance is much improved over raw but is a coating not an alloy: scratch through it, or leave sweat on it, and rust can start. Ayasa, who nitride DC04 with a post oxidation step, stopped offering a rust free guarantee on their raw and nitrided DC04 material in November 2023, which tells you how honest the industry has become about this.
Stainless steel, typically AISI 430 or a proprietary variant, resists corrosion through its chromium content rather than a surface layer. It is virtually rustproof in ordinary conditions. Acoustically it is usually longer sustaining, brighter, with a softer attack and more harmonic layering. Critics of stainless describe the brighter grades as tinny or wild, and long sustain has a cost: notes overlap more, so fast rhythmic playing can turn into a wash.
There is no correct answer. Players who play percussively and want note separation often prefer nitrided. Players who play slowly, use a lot of sustain and dislike maintenance often prefer stainless.
ANA-12What does gas nitriding actually do, and why did PANArt use it?#
intermediate
Short answer. Gas nitriding holds the steel in an ammonia atmosphere at roughly 500 to 580 degrees Celsius so that nitrogen diffuses into the surface and forms hard iron nitrides. It hardens the skin without quenching, so the shell does not distort, and PANArt used it because it gave them a sheet that was stiff and elastic enough to hold a tuned note without damping it.The metallurgy is well established outside music. Ammonia dissociates at the hot steel surface, freeing nitrogen that diffuses inward and combines with iron to form nitrides, principally Fe4N and Fe2 to 3N. Two zones result: a thin compound layer, often called the white layer, right at the surface, and beneath it a diffusion zone where nitrogen is dissolved in the lattice and fine nitride precipitates sit between the grains. In general engineering practice gas nitriding runs anywhere from about four hours to a hundred, and case depths of a few hundred micrometres are normal.
Two features matter for a handpan. First, the process runs well below the austenitising temperature of plain carbon steel, around 727 degrees Celsius, so there is no phase change and no quench. That means very little distortion, which is essential when your workpiece is a 1 mm hemisphere that has to stay round. Second, the hardening is a surface effect: the core stays ductile, so the shell can still take a hammer.
Handpan makers do not run engineering length cycles. On sheet a millimetre thick, a case a few hundred micrometres deep would be a large fraction of the wall. Ayasa describe their gas nitriding with post oxidation recipe as relatively brief compared with competitors, deliberately balancing sustain, workability and corrosion resistance. Longer cycles give more rust protection and a harder surface but make the shell harder to tune and can shorten sustain.
PANArt’s own framing was material science rather than protection. They described infusing nitrogen at 580 degrees to produce hard nitride crystals in a soft ferric matrix, giving a metal matrix composite with a high modulus of elasticity, high tensile strength, strong restoring force and low energy absorption. In plain terms: they wanted a sheet that springs back precisely and loses as little energy as possible to internal friction, because internal friction is what kills sustain.
The blue black colour on many nitrided instruments comes from the post oxidation step, not from the nitriding itself.
See also: ANA-17
ANA-13What do makers mean by “ember steel”?#
intermediate
Short answer. Ember Steel is a stainless steel formulation introduced by Ayasa Instruments in 2020, distinct from standard AISI 430 in composition and mechanical properties. It has since drifted into general use as a loose marketing term, and you should not assume two makers using the word mean the same alloy.Ayasa, run by brothers Ralf and Roy, arrived at it after roughly six years working with nitrided steel and testing a series of alternatives, including a high carbon steel they called Iddha. They settled on Ember in the summer of 2020. It is technically a stainless steel, but positioned between conventional nitrided DC04 and ordinary 430 stainless rather than being a variant of either.
The processing is different. Ember requires substantially higher annealing temperatures, quoted at between 550 and 650 degrees Celsius, against roughly 400 degrees for their nitrided work. That alone makes it a more demanding material to build with.
The claimed sound is long, controlled sustain with good note isolation and a responsive touch: longer sustain than nitrided steel but more controlled than plain stainless, and without the wild or tinny quality that some hear in bright 430 instruments. It does not rust in normal use and does not need oiling.
Two cautions. First, the exact composition is not publicly disclosed. Ember is a trade name, not a standards grade like DC04 or AISI 430, so you cannot look it up in a materials handbook. When a maker says Ember, ask whether they mean Ayasa’s material, shells bought from Ayasa, or their own similar stainless.
Second, “nitrided” has drifted in exactly the same way. It is a real, specific process, but the marketing use of the word covers a wide range of recipes with very different cycle lengths, case depths and post treatments. Two nitrided instruments from different workshops can differ more from each other than a nitrided one differs from a stainless one.
The useful takeaway is to treat material names as a starting point for a conversation with the maker, not as a specification. Ask what grade, what treatment, and how long the treatment runs. Makers who know their process will answer happily.
See also: ANA-18
ANA-14How does the choice of steel change the sound?#
intermediate
Short answer. Steel choice mainly moves three things: the sharpness of the attack, the length of the decay, and how much high frequency content sits in the tone. Nitrided instruments generally give a crisper attack and a shorter, more defined decay; stainless generally gives a softer attack, longer sustain and more brightness. Everything else being equal, though, the maker’s skill matters more than the material.The underlying mechanism is internal damping. Every time the steel flexes, a fraction of the energy becomes heat inside the metal rather than sound in the air. Alloys and heat treatments that lose less energy per cycle ring longer. That is why PANArt specified low energy absorption and high restoring force as design targets for their nitrided sheet, and why stainless, which is generally lower loss in this respect and also stiffer, tends to sustain longer.
What players actually report:
- Nitrided. Percussive, ceramic or gong like. Clear attack transient, quicker decay, good note separation. Suits rhythmic and fast playing, because notes get out of each other’s way. Some describe it as drier or more focused.
- Stainless (430 and similar). Notes ring out longer with a warm sustained tone that layers harmonically. Softer attack, smoother onset. Suits slow, meditative, ambient playing. The trade off is that fast passages can blur, and the brightest examples can sound thin or metallic.
- Ember and similar proprietary stainless. Positioned between the two: long but more controlled sustain, fuller and less metallic than plain stainless.
- Raw steel. Warm and soft, short lived in practice because it is rarely left untreated for long.
Long sustain also interacts badly with crossover, the wave interference in the air cavity that makes certain notes wobble. Saraz measured this in detail: on their 21 inch shells, B flat 4 shows the most intense interference in their note range, with typically 20 to 50 cents of wobble in the sustain no matter how well the note is tuned. The affected band shifts with shell diameter, sitting around C5 on 19 inch shells and B4 on 20 inch. A longer sustaining material simply gives you more time to hear that wobble.
Be sceptical of firm claims that one material is louder. Volume depends far more on tone field size, shell geometry and how you strike than on the alloy.
ANA-15Which steels rust, and how badly?#
beginner
Short answer. Raw steel rusts readily and needs constant care. Nitrided steel resists rust well but is not rustproof, and will corrode where the surface is worn, scratched or repeatedly exposed to sweat and salt air. Stainless, including Ember, is effectively rustproof in normal use.The difference is where the protection lives. Stainless protects itself through its bulk chemistry: chromium in the alloy forms a self repairing passive oxide film, so a scratch heals. Nitriding protects through a surface layer. Break the layer and the ordinary low carbon steel underneath is exposed, and it behaves like ordinary low carbon steel.
In practice, nitrided instruments are fine for most owners in most climates provided they are wiped down after playing and oiled occasionally. The situations that cause trouble are consistent and worth naming:
- Sweaty hands, especially salty sweat, left on the surface after a session.
- Coastal air. Salt laden humidity attacks nitrided surfaces persistently.
- Condensation from taking a cold instrument into a warm room and leaving it in a closed case.
- Water pooling inside the shell through the gu, which is the part nobody inspects.
- Wear at the ding and at the note centres where hands repeatedly land, which slowly polishes the compound layer away.
The industry has become notably more candid about this. Ayasa withdrew their rust free guarantee for raw and nitrided DC04 in November 2023, saying buyers may encounter rust spots despite protective measures. That is a straightforward statement of reality rather than a defect.
Stainless owners are not entirely exempt. Ferritic stainless can develop surface staining from iron particles picked up from other tools or from hard water, which looks like rust but is contamination sitting on top of an intact surface and usually cleans off. Genuine pitting on a 430 instrument is rare and normally means aggressive chemicals or prolonged salt exposure.
The one thing that damages every type is neglecting the inside. Air moves in and out of the port constantly, moisture comes with it, and there is no easy way to wipe the interior. Storing the instrument port down in a dry place, and never sealing a damp instrument in a case, does more good than any oil.
See also: ANA-16, CAR section
ANA-16What about coatings, oils and paint?#
intermediate
Short answer. Oils are the standard maintenance layer: a thin film that excludes moisture and needs reapplying. Lacquers and paints are permanent coatings applied by the maker. Anything you add yourself adds mass and damping to the tone fields, so thin and even is the rule.Oils. Almost every nitrided or raw instrument ships with advice to oil it. The purpose is simple: a molecular layer of oil keeps water and sweat off the steel. Makers commonly recommend a light mineral or specialist instrument oil, and some sell their own. The important technique points are that the film should be very thin, applied to a clean dry surface, and buffed off rather than left sitting. A thick oil layer collects dust, goes gummy and audibly damps the high partials.
Which specific oil to use is genuinely contested, and it is one of those topics where confident advice outruns evidence. Follow your maker’s recommendation, because they know what their surface treatment tolerates.
Lacquers and clear coats. Some makers apply a thin clear coat at the factory, and it is generally effective and stable. Applying one yourself is a bad idea. Coating thickness has a direct acoustic cost, uneven application detunes fields unevenly, and most coatings cannot be removed later without abrasives that will take the tuning with them.
Paint and decorative finishes. Painted handpans exist, usually as art pieces or on the mantle and bottom shell where the acoustic cost is lowest. Paint on tone fields adds mass and damping and will flatten the notes and shorten sustain. How much depends entirely on how thick it is. A maker who paints and then tunes has accounted for it; paint added after tuning has not been accounted for at all.
Historical curiosity. PANArt’s 2006 generation Hang carried an annealed brass coating over the nitrided steel with a brass ring around the circumference. This was a deliberate acoustic and protective choice by the makers, not decoration, and it was removed again in later generations.
The general principle: any layer you add is part of the vibrating system. Makers choose coatings before or during tuning so the tuner can compensate. Owners adding layers afterwards are changing an instrument that has already been finished.
See also: ANA-15
ANA-17How thick is the sheet, and why does it matter?#
advanced
Short answer. Most handpan shells start from sheet somewhere around 0.8 to 1.25 mm, with about 1 mm being the common reference point. Thickness sets how stiff the tone fields are, how much steel the tuner has to work with, how long the instrument sustains and how heavy it is.The concrete figures that makers publish cluster tightly. PANArt described deep drawing a nitrided sphere of 1 mm sheet. Ayasa publish 0.9 to 1.0 mm for their DC04 shells. Different makers and different shell sizes vary either side of that, and thickness is usually chosen alongside shell diameter and the intended note range rather than in isolation.
Why it matters:
Pitch and field size. The fundamental of a tone field rises with stiffness and falls with area. Thicker sheet is stiffer, so a given pitch needs a larger field. That is why low bass instruments are often built from thinner sheet on larger shells: both changes push in the same direction.
Tuning headroom. Hammering thins the metal locally. A tuner working a field is spending thickness, and there is a finite supply. Start from thin sheet and there is less room to correct partials, less room for future retuning, and a greater chance of the field going dead or developing a crack. Start too thick and the field becomes very hard to move at all, and the instrument is heavy.
Sustain. Thicker sheet generally sustains longer, all else equal, because a stiffer, more massive field stores more energy relative to what it loses per cycle. This is one of the reasons stainless instruments, which are often built slightly thicker to survive the harder working, tend to ring long.
Durability. A thicker shell tolerates a knock better and drifts less from heavy playing. Thin, heavily worked fields are where dents and cracks appear first.
Weight. Sheet thickness is one of the main levers on the instrument’s mass, alongside diameter and depth, which is why weights vary by a kilogram or more across otherwise similar instruments. See ANA-08.
Do not read thickness as a quality metric. It is a design choice made in combination with steel type, shell size and target scale. A maker who has settled on 0.9 mm for a high register instrument has probably thought about it more carefully than someone quoting a number as a selling point.
See also: ANA-08
ANA-18How can I tell what steel my instrument is made of?#
intermediate
Short answer. Ask the maker, and check your paperwork. There is no reliable home test, and in particular the magnet test does not work, because the stainless grades used in handpans are ferritic and therefore magnetic just like ordinary steel.The magnet myth is worth killing properly. People learn that stainless is non magnetic from kitchen equipment, which is usually austenitic 304 or 316. The stainless used for handpans is AISI 430 and relatives, which are ferritic: chromium without the nickel, and firmly magnetic. A fridge magnet sticks to a 430 handpan exactly as it sticks to a nitrided one. The test tells you nothing.
What does help:
Documentation. Most reputable makers state the material on the invoice, the website product page or a tuning report supplied with the instrument. That is the primary source and it is usually right.
Colour and finish. Nitrided instruments are typically dark grey to blue black, sometimes with a faint blue or purple sheen from post oxidation. Stainless is usually a lighter, greyer, more metallic silver, sometimes with a brushed or satin finish. This is suggestive, not proof: makers apply all sorts of finishes and some stainless instruments are darkened deliberately.
Rust behaviour over time. The most decisive everyday evidence. If small orange spots appear where your hands sit, or in the interior, the base metal is carbon steel with a surface treatment. Genuine stainless does not do this in ordinary conditions, though it can pick up surface staining that wipes off.
Sound and feel. Experienced players will make a guess from the attack and decay: crisper and shorter suggests nitrided, longer and brighter suggests stainless. It is a reasonable guess and often wrong, because build quality and shell size push in the same directions.
If the instrument is second hand with no history and the maker is unknown or unreachable, accept that you may not find out. In that case treat it as nitrided for care purposes, meaning wipe it after playing and oil it occasionally. That regime is harmless on stainless and necessary on everything else.