Aluminum Hokotol
also Aleris Hokotol
Hokotol is an AlZnMgCu (7000 series) high-strength pre-stretched thick plate from Aleris (now Novelis), with composition and heat treatment set to give uniform strength, sound through-thickness properties and very low residual stress in sections up to about 250–300 mm.
Hokotol tempers and conditions
Hokotol is supplied in 4 conditions, soft to hard.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
T74, stress relieved by stretching | Pick for thick machined tooling and structural blocks where residual stress, toughness and stress-corrosion resistance matter more than peak strength. | 460 | 525 | 7 | 155 HB | 41 % IACS |
As-supplied high-strength plate | Default stock condition for Hokotol plate: best balance of ~480 MPa yield, low residual stress and stable machining for moulds and jigs. | 480 | 540 | 6 | 165 HB | 39 % IACS |
T76, stress relieved by stretching | Compromise temper: near-T6 strength with markedly better exfoliation/SCC behaviour than peak-aged plate. | 485 | 545 | 6 | 162 HB | 38 % IACS |
T6, stress relieved by stretching | Choose when maximum strength and hardness are required and the part will not see humid/chloride SCC service. | 505 | 565 | 5 | 172 HB | 33 % IACS |
What is Hokotol?
Hokotol is an AlZnMgCu (7000 series) high-strength pre-stretched thick plate from Aleris (now Novelis), with composition and heat treatment set to give uniform strength, sound through-thickness properties and very low residual stress in sections up to about 250–300 mm. It is used as machining stock for blow and injection mould tooling, large fixtures and aerospace structural parts, machining more predictably and holding size better than standard 7075 thick plate. Limits are poor weldability, sensitivity to stress-corrosion and exfoliation, low formability and a service ceiling of roughly 120–130 °C. Hokotol has a density of 2.82 g/cm³ (0.102 lb/in³), heavier than 89% of aluminum grades. It melts at 477°C (891 °F). Hokotol has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 540 MPa (78.3 ksi) — stronger than 95% of aluminum grades. Elongation at break is 6% and the elastic modulus is 71 GPa (10.3 Msi).
What is Hokotol used for?
- Injection mould tooling
- Blow mould cavities and blocks
- Compression moulds
- Large machining and assembly fixtures
- Thermoforming and vacuum tools
- Aerospace machined structural blanks
Advantages
- High strength — 480 MPa (69.6 ksi), better than 95% of aluminum grades
- Easy to machine — 82/100, better than 94% of aluminum grades
- Polishes to a fine finish — 75/100, better than 90% of aluminum grades
- Tough — resists crack growth — 32 MPa·√m (29.1 ksi·√in), better than 83% of aluminum grades
Limitations
- Difficult to weld — 18/100, worse than 94% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
- Needs corrosion protection — 40/100, worse than 75% of aluminum grades
Hokotol properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
Hokotol has a density of 2.82 g/cm³ (0.102 lb/in³), heavier than 89% of aluminum grades. It melts at 477°C (891 °F).
Mechanical12
Hokotol has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 540 MPa (78.3 ksi) — stronger than 95% of aluminum grades. Elongation at break is 6% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
Hokotol is rated for continuous service to 120°C (248 °F). It conducts heat at 150 W/m·K (86.7 BTU/hr·ft·°F), better than 58% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
Hokotol conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 75% of aluminum grades.
Sustainability4
Producing a kilogram of Hokotol takes about 155 MJ of energy and emits 12 kg of CO₂ — less than 94% of aluminum grades. Typical recycled content is 25%.
Manufacturability7
Hokotol's machinability is very good (82/100, better than 94% of aluminum grades); weldability poor (18/100); formability poor (18/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. Hokotol is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Hokotol
Is Hokotol easy to machine?
Excellent high-speed machining with polished-flute carbide tools, large positive rake and flood or MQL cooling; low residual stress means minimal distortion when hogging deep mould cavities.
Can Hokotol be welded?
Essentially not arc-weldable (hot cracking, large strength loss in the HAZ); join mechanically or use inserts, and repair only by qualified friction-stir or specialist procedures.
Can Hokotol be formed, bent or molded?
Supplied as aged thick plate — no cold forming; shape by machining, and avoid re-solution treating locally since properties depend on the mill quench.
Manufacturability
The process limits FabDigit applies to Hokotol. Every Hokotol part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Excellent82 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Hokotol chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Znproprietary AlZnMgCu chemistry; range given from the 7010/7050/7075 family the alloy belongs to | 5.5 – 7 | 6.2 |
| Mg | 1.8 – 2.6 | 2.2 |
| Cu | 1.2 – 2 | 1.6 |
| Zrgrain-structure control in thick plate | 0.05 – 0.16 | 0.11 |
| Cr | 0 – 0.2 | |
| Mn | 0 – 0.2 | |
| Fekept low for toughness | ≤ 0.15 | |
| Si | ≤ 0.12 | |
| Ti | ≤ 0.06 | |
| Al | balance |
What surface finishes work on Hokotol?
Hard-anodize or Ni-plate mould surfaces for wear and gas resistance; clear decorative anodize looks grey, so paint or chromate-free conversion coating is preferred for humid environments.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum Hokotol in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Aleris Hokotol
How much does Hokotol cost?
Hokotol is a premium-cost aluminum ($$$), pricier than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Hokotol — frequently asked
What is Hokotol used for?
Hokotol is typically used for injection mould tooling, blow mould cavities and blocks, compression moulds, large machining and assembly fixtures, thermoforming and vacuum tools and aerospace machined structural blanks. In short: premium mold plate.
What is the yield strength of Hokotol?
Hokotol has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 540 MPa (78.3 ksi) — stronger than 95% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is Hokotol easy to machine?
Yes — machinability is rated very good (82/100, better than 94% of aluminum grades). Excellent high-speed machining with polished-flute carbide tools, large positive rake and flood or MQL cooling; low residual stress means minimal distortion when hogging deep mould cavities.
Can Hokotol be welded?
Not readily — weldability is rated poor (18/100). Essentially not arc-weldable (hot cracking, large strength loss in the HAZ); join mechanically or use inserts, and repair only by qualified friction-stir or specialist procedures.
What surface finishes work on Hokotol?
Hard-anodize or Ni-plate mould surfaces for wear and gas resistance; clear decorative anodize looks grey, so paint or chromate-free conversion coating is preferred for humid environments.
Can Hokotol be formed, bent or molded?
Supplied as aged thick plate — no cold forming; shape by machining, and avoid re-solution treating locally since properties depend on the mill quench.
What is the maximum service temperature of Hokotol?
Hokotol is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Hokotol cost?
Hokotol is a premium-cost aluminum ($$$), pricier than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in Hokotol?
Yes — Hokotol is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- Hokotol high-strength aluminium plate product information — Aleris / Novelis Rolled Products (2019)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys (7000-series wrought alloys) — ASM International (1990)
- MMPDS-17, 7050/7010/7075 thick plate T6x and T74x design values — Battelle/FAA (2022)
- EN 485-2 / ASTM B209 — aluminium plate mechanical property requirements — CEN / ASTM (2021)
- ASM Handbook Vol. 13B — corrosion of aluminium alloys — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.