Q69 vs QH69: Which One Actually Cleans H-Beams Properly?
[By Ding Renxiang, Chief Engineer & Technical Director | ATHI]
The Problem with Blasting H-Beams on a Standard Machine
H-beams have geometry that fights back. The inner surfaces of the flanges and the web-to-flange junction are sheltered from the abrasive stream when blast wheels are positioned for flat work. I’ve inspected plenty of H-beams that came out of a standard machine looking great on the outside but still carrying rust and scale inside the flanges.
This matters because structural steel coatings need to cover all surfaces — including the ones you can’t see once the beam is erected. If the inner flanges aren’t properly cleaned, you’re building a corrosion problem into the structure.
When the Standard Q69 shot blasting machine Is Enough
The Q69 handles H-beams fine when:
- H-beams are only part of your workload — you also process plates, channels, and fabricated parts
- The beams have a relatively square cross-section (height roughly equal to width)
- You’re targeting Sa 2 or basic Sa 2½ and can accept minor residue in hard-to-reach areas
- Mixed-workpiece versatility matters more than absolute H-beam cleaning perfection
When You Need the QH69 H-beam shot blasting machine
The QH69 is worth specifying when:
- H-beams and tall structural sections are your primary workload
- Section height significantly exceeds width (think HW 400×400 and above, or HM/HN series)
- You must achieve Sa 2½ or Sa 3 on all surfaces including deep inner flanges
- Your coating spec or structural code doesn’t allow any cleaning shortcuts
What’s actually different? The QH69（H-beam shot blasting machine）repositions blast wheels to fire laterally into the web-flange junction, instead of primarily top-down. It’s not a dramatically different machine — it’s the same platform with a different wheel layout optimized for tall cross-sections. The price difference is modest compared to the risk of coating failure on improperly cleaned beams.
Honest caveat: For very large, irregular welded assemblies (box columns, complex trusses), neither the Q69 nor QH69 may be the best choice. Those workpieces often need a hanger-type or tunnel-type machine that can rotate or reposition them. We’ll tell you if that’s the case.
Beyond H-Beams: Structural Steel Blasting Equipment
Structural steel blasting equipment isn’t limited to H-beams. Angle steel, channel steel, box sections, welded columns — the Q69 platform handles all of these with adjustable blast windows and modular wheel configurations. Our longest standard conveyor reaches 18,000 mm, and for customers running continuous steel structure lines, we integrate the blasting machine with automatic loading, paint booths, and drying ovens.
About Antai Heavy Industry (ATHI)
Qingdao Antai Heavy Industry Machinery Co., Ltd. (ATHI) is a premier provider of shot blasting and surface treatment solutions. We are dedicated to delivering efficient, eco-friendly, and intelligent machinery to customers worldwide through continuous technological innovation and global cooperation.
