Material Description
Molybdenum is a refractory metal used where service temperatures, thermal conductivity or dimensional stability rule out steel and nickel alloys. In scrap form it arrives from three broad places: high-temperature furnace internals that have reached end of service, production scrap from the manufacture of mill products and components, and equipment removed during plant upgrades in the glass, solar, semiconductor and heat-treatment industries.
The stream is not chemically uniform. Unalloyed molybdenum, lanthanated and yttriated grades, TZM (titanium-zirconium-molybdenum) and molybdenum-copper or molybdenum-lanthanum composites all circulate under the loose commercial heading of 'moly scrap'. They behave differently in downstream processing, so identification matters more here than in commodity streams.
Chemistry is grade-dependent. This page does not state a guaranteed composition: alloy family, element ranges and any deleterious-element limits must be confirmed for the specific lot by material identification, XRF or OES analysis, mill certificates where available, or an agreed inspection before shipment.
Accepted Forms
Material is normally offered in one or more of the following physical presentations. A lot containing several forms should be packed and described fraction by fraction rather than as a single average.
- •Sheet, plate, foil and strip offcuts from fabrication
- •Rod, bar, tube and machined component rejects
- •Furnace hot-zone parts: shields, heating elements, boats, racks and support structures
- •Sputtering target backing plates and spent target remnants where the moly body is recoverable
- •Electrodes, feedthroughs and glass-melting components
- •Turnings, chips and solid machining offcuts, kept separate from solids
- •Wire, mesh and thermocouple sheathing in clean, identified condition
Typical Alloy Families
Because processors buy molybdenum for what it can be returned into, the alloy family present in the lot is a first-order commercial question rather than a technical footnote.
- •Unalloyed (commercially pure) molybdenum — the simplest and most widely accepted form
- •TZM — molybdenum with small titanium and zirconium additions and a controlled carbon level
- •Lanthanum-oxide and yttrium-oxide doped molybdenum used for high-temperature creep resistance
- •Molybdenum-copper and molybdenum-tungsten composites, which are evaluated as composites and not as pure moly
- •Moly-bearing ferroalloy and catalyst residues, which are an entirely different trade and are not covered by this specification
Identification and Sorting
The two identification errors that cost money in this stream are confusing molybdenum with tungsten, and confusing it with stainless or nickel alloy sheet. Tungsten is very much denser than molybdenum — roughly double for the same volume — so weight in the hand separates the two quickly once a reference piece is available. Against stainless, molybdenum is non-magnetic in the practical workshop sense, has a distinctly grey metallic appearance, and is markedly heavier than a stainless part of the same size.
Surface condition complicates all of this. Hot-zone parts arrive oxidised, sometimes with a yellow-grey molybdenum oxide bloom, and oxidised surfaces mislead both the eye and a handheld analyser. A ground or filed clean spot is normally needed before any instrument reading is meaningful.
Sorting expectations are simple to state and worth following: keep unalloyed material apart from TZM and doped grades where the generator knows the difference, keep turnings apart from solids, and keep composite and clad items in their own fraction.
Contamination and Exclusions
Molybdenum lots are usually rejected or discounted for what travels with the metal, not for the metal itself.
- •Stainless steel, nickel alloy and mild steel fixings, frames, brackets and fasteners
- •Ceramic insulators, refractory fibre, graphite felt and furnace insulation attached to hot-zone parts
- •Copper braid, brazed joints, plating and cladding on feedthroughs and composite items
- •Heavy oxidation and scale where it makes up a significant share of piece weight
- •Cutting fluid, oil, grinding sludge and free moisture in turnings drums
- •Radioactively contaminated or otherwise process-contaminated equipment, which is excluded from this stream
- •Tungsten pieces mixed into a moly lot — these belong in the tungsten stream and are separated before evaluation
Preparation and Packaging
Preparation aims at two things: removing non-molybdenum mass and presenting the lot so that each fraction can be judged on its own merits. Loose insulation and fasteners removed at source almost always improve the commercial outcome for the seller more than the labour costs.
- •Steel drums, boxes or strapped pallets, filled by weight rather than volume
- •Turnings drained of free liquid and packed separately from solids
- •Sheet and plate stacked and banded; sharp fabricated offcuts contained to protect handling staff
- •Each package labelled with lot reference, fraction description, alloy family where known, and net weight
- •Photographic record of packed fractions retained in the lot file
Buyer and Seller Specification Notes
An enquiry that carries the following information can normally be answered without a second round of questions: the alloy family or a statement that it is unknown, the physical forms and their approximate weight split, the origin process, the surface condition, whether analysis or mill documentation exists, packing available at the loading point, and the destination port.
Where a buyer needs assured values, those values belong in the sales contract together with the sampling protocol, the analysis method, the acceptance window and the consequence of a result outside it. Nothing on this page performs that function.
Specification Table
The table records typical procurement characteristics for this stream. Values that depend on grade or lot are stated as such — they are not guaranteed figures and do not replace a contractual specification.
| Material category | Molybdenum and molybdenum alloy scrap (secondary raw material) |
|---|---|
| Accepted forms | Sheet, plate, foil, rod, bar, tube, hot-zone parts, boats, shields, electrodes, machined rejects, turnings |
| Typical alloy families | Unalloyed molybdenum, TZM, lanthanated and yttriated grades; Mo-Cu and Mo-W composites evaluated separately |
| Composition | Chemistry is grade-dependent. This page does not state a guaranteed composition: alloy family, element ranges and any deleterious-element limits must be confirmed for the specific lot by material identification, XRF or OES analysis, mill certificates where available, or an agreed inspection before shipment. |
| Identification | Density comparison against tungsten and stainless, magnetic behaviour, appearance on a ground clean spot, XRF or OES screening on prepared surfaces |
| Common contamination | Steel and stainless fixings, ceramic and refractory insulation, copper braid, plating, heavy oxide, oil and grinding residue |
| Exclusions | Radioactive or process-contaminated equipment, catalyst and chemical residues, moly-bearing ferroalloy, sealed pressurised assemblies |
| Preparation | Insulation and fasteners removed where practical; turnings drained and packed separately from solids |
| Typical packaging | Steel drums, boxes or banded pallets filled by weight, labelled by fraction and net weight |
| Inspection | Third-party inspection can be arranged at the loading location; scope and appointment agreed in the sales contract |
| Evaluation basis | Recoverable molybdenum content expected by the processing route, less non-moly attachments, contamination and handling burden |
| Documentation | Commercial invoice, packing list and transport documents; mill certificates or analysis where they exist and have been agreed; waste-shipment and customs documentation as required by the specific trade lane |
Inspection and Analysis
Two distinct activities are both loosely called 'analysis' and should not be confused. Screening separates molybdenum from tungsten, stainless and nickel alloys and flags anomalies before packing; it is an operational tool. Contractual analysis establishes an agreed figure and requires a written sampling protocol, a named method and an accepted laboratory.
For molybdenum, prepare the surface before any reading: oxide, paint and machining residue distort results. Elements normally of interest are molybdenum, tungsten, titanium, zirconium, nickel, chromium, iron and copper — iron and chromium indicating steel carry-over, titanium and zirconium pointing to TZM, and copper indicating composite or clad material.
Limitations of screening analysis
- •Handheld XRF reads a small surface area of the piece it is pointed at; scale, paint, plating, coatings, oxide and machining residue all bias that reading.
- •Handheld instruments read alloying elements well but are weak or blind on light elements — carbon in particular — so they cannot separate grades that differ mainly by carbon content.
- •A reading on one piece is not a lot average. Mixed-grade lots require representative sampling across packages, layers and size fractions before a figure is treated as commercially meaningful.
- •Screening results are used to sort and to open a price discussion. Contractual figures require the sampling protocol, laboratory method and acceptance criteria the parties have agreed in writing.
Inspection scope, appointed inspector and sampling protocol are set out on our inspection services page and must be agreed in the sales contract before shipment.
Customs Classification
Customs classification for molybdenum-bearing secondary material depends on the actual composition and physical form of the goods, on whether the material is solid scrap, turnings, powder or residue, on the destination country and on how the competent authority in that jurisdiction interprets the material description.
Mixed-grade and mixed-family lots can create additional classification complexity, because the description of the goods on the invoice and packing list must reflect what is actually shipped rather than the best fraction in the load.
Nautica does not assign a definitive tariff code in advance for this stream. Buyers and importers should confirm the applicable classification, duty treatment and any import licensing or waste-shipment obligation with their own customs broker or the competent customs authority for the destination before contracting.
Frequently asked questions
Technical and Commercial Disclaimer
This document describes typical characteristics of a secondary raw material stream. Scrap of this type is heterogeneous by nature: composition, alloy or binder content, contamination and recoverable content vary between lots and within a single lot.
Nothing on this page constitutes a guaranteed specification, a warranty of composition, a declaration of purity or an offer capable of acceptance. Guaranteed specifications, tolerances, sampling protocol, analysis method, acceptance criteria, deduction mechanics and rejection rights exist only where they are written into the signed sales contract between buyer and seller for a specific lot.
Where a buyer requires assured values, those values must be defined contractually and verified by an agreed inspection or analysis procedure before shipment.
Document reference: /specifications/molybdenum-scrap · Last reviewed 2026-08-14.