Inleiding
7005 is a 7000-series aluminum alloy known for one thing 7xxx grades usually lack: strong weldability. Its zinc-magnesium base is balanced with manganese, which keeps strength high while letting welded assemblies recover much of their strength through post-weld aging. The decision usually comes down to whether you need weldable high strength – where 7005 beats 6061 aluminium – or maximum peak strength, where 7075 aluminium takes over.
What Is 7005 Aluminium Alloy?
7005 is part of the 7xxx series, with zinc as the main alloying element and magnesium forming the strengthening phase. Manganese (0.20-0.50%) and a small chromium addition improve strength and corrosion behavior. Typical composition: Zn 4.0-5.0%, Mg 1.0-1.8%, Mn 0.20-0.50%, Cr 0.06-0.20%, balance aluminum. Density is about 2.78 g/cm3.
Typical Properties by Temper
| Temper | Ultimate Tensile (MPa) | Rekgrens (MPa) | Rek (%) | Opmerking |
|---|---|---|---|---|
| T5 | ~345 | ~290 | ~12 | Extruded and aged (most common) |
| T6 | ~350 | ~305 | ~11 | Solution heat treated and aged |
| T53 | ~330 | ~285 | ~11 | Welded then artificially aged to recover strength |
Values are representative typical figures; confirm against the mill test certificate for the specific lot.
7005 vs 6061 vs 7075
| Alloy | Rekgrens (MPa) | Ultimate Tensile (MPa) | Lasbaarheid | Corrosion | Best fit |
|---|---|---|---|---|---|
| 6061-T6 | ~276 | ~310 | Uitstekend | Goed | Versatile structural, easy forming |
| 7005-T5 | ~290 | ~345 | Uitstekend | Moderate-good | Welded high-strength frames |
| 7075-T6 | ~503 | ~572 | Slecht | Limited | Aerospace, peak strength |
Toepassingen
- Bicycle frames and welded sporting equipment
- Automotive structural components and armor plate
- Rail vehicle bodies and welded fabrications
- Structural extrusions where weldability and strength both matter
Welding, Machining, and Corrosion Limits
7005 is the most weldable of the common 7xxx alloys. It is typically welded with 5356 or 5039 filler, then artificially aged (T53/T63) to recover most of the lost strength. Machining is fair – harder than 6061, so use sharp tooling. Corrosion resistance is good among 7xxx grades but still below 6000-series; coat or anodize for marine or saltwater exposure.
Go/No-Go Limits
Use this quick reference to decide whether 7005 fits your part.
Go – use 7005 when:
- Yield above ~290 MPa is needed in a welded assembly – 7005-T5 with post-weld aging is a standard fit (bicycle frames, rail bodies, armor).
- Weldability matters more than peak strength – 7005 welds and re-ages where 7075 cannot.
- Moderate corrosion exposure with coating is acceptable – anodizing or paint keeps it serviceable.
No-Go – do not use 7005 when:
- Peak aerospace strength (above ~500 MPa yield) is required – 7075 or 7055 are the right grades.
- Aggressive marine or chloride immersion without coating is expected – 6000-series or 5083 resist better.
- Heavy cold forming after aging is planned – 7xxx tempers crack; form before heat treatment.
Conclusie
7005 is the weldable high-strength 7xxx grade: stronger than 6061 and far more weldable than 7075, but its corrosion resistance still trails the 6000-series and stock of non-standard tempers can be tight. Linsy Aluminum stocks 7005 plate, bar, and extruded profiles and supplies custom dimensions at low minimum order quantities, with full MTC documentation and in-house processing and surface treatment. If your part sits between strength and weldability on the 7xxx curve, send the drawing for a grade-fit and temper review.
Veelgestelde vragen
Is 7005 stronger than 6061?
Yes. 7005-T5 has a higher yield (~290 MPa vs ~276 MPa) and tensile (~345 MPa vs ~310 MPa) than 6061-T6, while 6061 forms, anodizes, and resists corrosion more easily. Choose 7005 for strength-in-a-weld, 6061 for versatility.
Can 7005 be welded?
Yes – it is the most weldable common 7xxx alloy. Welding with 5356/5039 filler followed by artificial aging recovers most of the heat-affected-zone strength.
What is the best temper for welded frames?
T5 extrusions are standard; for welded structures, a T53 route (weld then age) recovers strength that the weld heat would otherwise remove.
How well does 7005 resist corrosion?
Moderately well for a 7xxx grade, but below 6061. Use anodizing or paint for outdoor and marine atmospheres, and avoid bare saltwater immersion.
What documents come with an order?
Linsy issues an MTC for every order. SGS chemical, mechanical, ultrasonic, and RoHS+REACH test reports are available on request at extra cost.
