Nickel alloy questions, answered
One page per question
These are the questions that arrive before a grade has been chosen, and the ones that cut across the whole catalogue. Each has its own page: the short answer at the top, the detail underneath.
If your question is about one material, the grade page carries its chemistry, standards and forms. If it is about the choice between materials, the comparison notes and the cross-reference are the faster route.
Choosing a grade
What is the difference between a nickel alloy and a stainless steel?
Stainless steel is iron with at least 10.5 % chromium; the chromium oxide film is what makes it stainless. A nickel alloy is nickel-based, usually well above 50 % nickel, and it keeps its strength and corrosion resistance where an iron-based alloy gives up: above roughly 600 °C, or in chlorides and reducing acids.
Read the full answerAre Inconel, Hastelloy and Monel different metals?
They are trade names, not chemistries. Inconel covers nickel-chromium grades, Hastelloy covers both nickel-molybdenum and nickel-chromium-molybdenum grades, and Monel is nickel-copper. Each name maps to a UNS number, a DIN number and a GB designation.
Read the full answerIs a heat-resistant alloy the same as a corrosion-resistant one?
No. Heat resistance is creep strength plus a stable oxide scale at temperature; corrosion resistance is behaviour in a specific aqueous medium. The alloying that delivers one usually works against the other, which is why Hastelloy X and Hastelloy C-276 are not interchangeable despite sharing a family name.
Read the full answerI need to work above 900 °C. What decides the choice?
Oxide-scale stability and creep strength decide it, not melting point. Every grade here melts above 1260 °C, but the temperature a part can actually run at is far lower. Above 900 °C the shortlist is Hastelloy X, Inconel 617 and Inconel 602CA, with cast Inconel 713C for turbine hardware.
Read the full answerWhy does the same grade cost so much more from one supplier than another?
Melting route, cleanliness, inspection level and paperwork. The same UNS number can be vacuum induction melted and ESR refined, or air melted, and those are not the same product even though both meet the composition. Ask which melting route the quote is based on before comparing prices.
Read the full answerSpecifications and standards
How do UNS, DIN and GB numbers line up?
They are three numbering systems for the same material. UNS is the American five-character scheme, DIN or Werkstoff is the German number, and GB is the Chinese designation. A drawing may name any one of them, and the chemistry windows are not always identical.
Read the full answerWhat is the difference between EN 10204 3.1 and 3.2?
Who signs it. A 3.1 certificate is issued by the manufacturer's authorised inspection representative, drawn from the actual heat. A 3.2 certificate additionally requires an inspector independent of the manufacturer, which means a third party is involved in or witnesses the testing.
Read the full answerWhat is the difference between an ASTM and an AMS specification?
Scope and audience. ASTM covers the alloy for general industry: composition, mechanical properties, dimensions and tolerances. AMS is the SAE aerospace material specification and usually adds process control, cleanliness, grain size and inspection requirements on top. Aerospace drawings cite AMS; industrial ones usually cite ASTM.
Read the full answerIs meeting the chemical composition enough?
No. Composition is the entry ticket. Delivery condition matters as much: solution annealed against solution treated and aged, the mechanical results that follow from it, grain size where the standard controls it, and the non-destructive testing level. Two heats with identical chemistry behave differently in service if the heat treatment differs.
Read the full answerOrdering and delivery
What do you need from me to quote?
Grade or duty, product form, size, quantity, the governing standard, delivery condition and inspection level. Missing any one of them usually costs a round of email. If you only know the duty and not the grade, send the medium, the temperature and the pressure — those tell us more than a grade name picked from a table.
Read the full answerHow are the minimum order quantity and lead time set?
By the melt, not by a price list. A heat has a minimum weight, so the smallest order depends on the grade and the section size. Grades we hold in stock ship from stock; grades that have to be melted are scheduled into the furnace. We quote both figures as firm numbers rather than as a rule of thumb.
Read the full answerCan you melt a grade that is not on your list?
Yes, against a drawing or a standard, provided the composition range and the applicable specification are defined. What we will not do is guess a chemistry: if the drawing gives only a trade name and no standard, we ask which specification applies before quoting.
Read the full answerFabrication and processing
Are nickel alloys difficult to weld?
It depends entirely on the grade, so a blanket answer would be misleading. 625 and 600 weld readily with matching filler. 718 is weldable but needs solution treatment and ageing afterwards to restore its properties. Cast gamma-prime alloys such as 713C are effectively not weldable, and that is a property of the alloy rather than a limitation of the shop.
Read the full answerWhy can Inconel 713C not be forged or rolled?
Because of the same elements that make it strong. 5.5-6.5 % aluminium and 0.5-1.0 % titanium form a high volume fraction of gamma-prime Ni3Al, and that precipitate cracks under hot working. 713C is melted and cast, and it is supplied as remelt stock and cast bar for investment casters, not as wrought bar or plate.
Read the full answerDoes cold-worked material need heat treatment afterwards?
Usually yes. Cold working hardens the alloy, reduces ductility and leaves residual stress, so a solution anneal is normally needed to restore both the mechanical properties and the corrosion resistance — particularly resistance to chloride attack in the austenitic grades.
Read the full answerAre nickel alloys magnetic?
Mostly not. The austenitic nickel alloys and the nickel-copper grades are non-magnetic in the annealed condition, which is why Monel appears in instrument and sensor work. Grades with a substantial iron content, such as 718, are noticeably magnetic, and heavily cold-worked parts can show weak magnetism even in normally non-magnetic grades.
Read the full answerStill not answered?
Send the duty, the medium and the temperature. We will tell you which grade fits and which one does not.