Product Category
IT5 Joint · ≤0.005mm Runout · −45% Weight · Hollow
RAL / 001 — 008
Lightweight CNC Machined
Robot Arm Links
Custom precision robot arm links — hollow tubular and prismatic designs in Al 7075 and Ti Grade 5. Joint interface bores IT5, end-flange runout ≤ 0.005 mm, minimum weight with maximum torsional stiffness. For 6-DOF industrial, collaborative, and custom robotic arms.
IT5
Joint Bore
≤0.005mm
Flange Runout
−45%
vs Solid
PART DWG · RAL-000 UPPER ARM LINK · Al 7075-T6 HA
ISO 9001 · MOQ 1 PC
Joint Bore IT5
Hollow Tube
Cobot · Industrial · Aero · Med · Service · SCARA
Use Cases
Al 7075 · 6061 · Ti Gr5 · CFRP Hybrid
Materials
48hr Quote · 7-Day Proto
Service
IT5
Joint Interface
bore tolerance class
bore tolerance class
≤0.005mm
End Flange Runout
concentricity
concentricity
−45%
Weight vs Solid
hollowed Al 7075
hollowed Al 7075
7 Days
Fastest Delivery
prototype orders
prototype orders
Why It's Difficult
Robot Arm Link Challenges
A robot arm link must be simultaneously stiff (resist bending under payload), light (minimise motor torque demand), and accurate (interface bores and flanges concentric for zero backlash).
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Weight vs Stiffness
Rotational inertia of the link multiplied by gear ratio² determines the servo motor demand. HXC optimises wall thickness and hollow profile to achieve maximum stiffness per gram.
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Interface Concentricity
Both end bores must be concentric and parallel within tolerance — any misalignment creates a kinematic error in the robot's reach. All interface features are machined in one setup.
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Torsional Strength
Robot arm links carry torsion from wrist torque reactions. Tube wall thickness, rib placement, and cross-section shape are designed to maximise torsional stiffness without adding weight.
Our Work
Request Similar Part →
Robot Arm Links We've Made
Upper arm, forearm, and wrist link components for collaborative and industrial robots.
Capabilities & Tolerances
What We Can Deliver
Typical specifications for this product type. Confirm exact requirements at enquiry.
| Joint bore tol. | IT5 |
| Flange runout | ≤ 0.005 mm |
| Arm length tol. | ±0.05 mm |
| Parallelism | ≤ 0.01 mm / 100 mm |
| Weight reduction | 40–50% vs solid |
| Min wall thickness | 2 mm (load zones) |
| Materials | Al 7075, Al 6061, Ti Gr5, CFRP hybrid |
| Cross-section | Circular, rectangular, pocket-milled |
| Surface treatment | Type II / III anodize, passivate |
| MOQ | 1 pc (prototype) |
| Lead time (proto) | 7–10 days |
| Lead time (production) | 18–28 days |
How It Works
From Drawing to Finished Part
Upload your 2D/3D file — receive DFM feedback, quote, and confirmed lead time within 48 hours.
01
Upload Drawing
STEP, DXF, PDF or sketch. 2D + 3D preferred.
02
DFM Review & Quote
Free DFM feedback + material, lead time, and cost — within 48 hours.
03
CNC Machining & QC
5-axis CNC, CMM inspection, full dimensional report.
04
Ship Worldwide
DHL / FedEx / sea freight. Inspection report enclosed.
Reviews
Trusted by Engineers Worldwide
★★★★★
"The CMM report matched our incoming inspection perfectly. Every critical dimension was within spec on the first article. Lead time exactly as quoted."
AK
Alex K.
Mechanical Engineer · Germany
★★★★★
"HXC's DFM review caught a tolerance stack issue before we committed to production. The finished parts were perfect and batch consistency was excellent."
SL
Sophie L.
Design Engineer · France
★★★★★
"We've sourced over 30 part numbers from HXC across three years. Quality is consistent, lead times are reliable, and the engineering team is always responsive."
JT
James T.
Senior Buyer · UK
FAQ
Robot Arm Link — FAQ
Common questions from engineers and procurement teams — answered by our manufacturing team.
A robot arm link is the structural segment between two robot joint housings — it transmits the torque and forces generated at each joint to the next, while minimising rotational inertia seen by the servo motors. The link's end-interface bores must be concentric, parallel, and at the correct distance to achieve the robot's reach specification.
For a 6-DOF robot, link inertia is reflected through the gear ratio² of each upstream joint. Reducing link weight by 30% allows the joint motor to accelerate the arm faster, extend the reach, or handle a larger payload with the same motor. HXC calculates the inertia reduction achievable from hollowing before quoting.
HXC offers: Circular hollow section (best torsional stiffness per weight); rectangular hollow (better bending stiffness in one plane — for SCARA arms); complex pocket-milled section (topology-optimised, maximum stiffness per gram, higher cost). The optimal section is selected during DFM review based on your arm's load case.
Both end bores: IT5 tolerance class. End flange face runout to bore axis: ≤ 0.005 mm. Distance between end bores (arm length): ±0.05 mm. Parallelism between the two bore axes (determines robot kinematic accuracy): ≤ 0.01 mm per 100 mm of arm length — verified by CMM.
Yes — mirrored and scaled variants of an arm link design can be produced from the same CAD model family. HXC can produce a set of 3–4 link sizes (scaled versions) with consistent interface standards and verified CMM reports — useful for modular robot arm platforms.
Al 7075-T6 hard anodized: standard for collaborative robots — 2.8 g/cm³, high strength, excellent machinability. Ti Grade 5: aerospace and high-performance cobots — 30% lighter than Al 7075 for the same stiffness, higher cost. CFRP with machined Al inserts: highest specific stiffness — hybrid design available.
Yes — symmetric arm link pairs are produced from the same CMM program with left/right mirror symmetry verified. All critical interface dimensions (bore diameter, flange face runout, arm length) are matched to within the tolerance class specification.
Prototype: 7–10 days. Small batch (50–200 pcs): 12–18 days. Production: 18–28 days. Ti Grade 5 links add 3–5 days.
Get a Quote
Send Your Drawing.
Get a Quote.
Every enquiry includes a DFM review — tolerance feasibility, material confirmation, and process approach confirmed before production starts. MOQ 1 piece.
24hr
Quote Response
MOQ 1
Prototypes OK
ISO
9001:2015
📐
DFM Review on Every Enquiry
Tolerance feasibility, fixturing strategy, and material confirmation. Specific, actionable feedback — not generic pushback.
🎯
First Article Inspection — Standard
FAI report on every new run. Material certs and surface treatment certs included with every shipment.
🔄
Same Process: Prototype to Production
Process plan from your prototype applies to production batches. No re-qualification when you scale.
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3 / 4 / 5-Axis CNC + Turning
Complex structural parts, shafts, housings, and transmission components. Metals and engineering plastics.
ISO 9001:2015
3/4/5-Axis Milling
CNC Turning
CMM Inspection
Global Delivery