Guangzhou Liantuo Machinery Trading Company

After more than a decade in the excavator parts business, we know one thing for sure: customers don't fear a slightly higher price — they fear parts that fail shortly after installation. Every hour of downtime can cost hundreds of dollars.

That’s why our quality control isn't about filling out forms or passing audits. It’s about one practical goal: making sure the parts you install last long and work without trouble.

To be honest, we made mistakes in the early days. One batch of pins had insufficient hardness, and the customer saw abnormal wear after only 200 hours. Since then, we've built three non-negotiable steps into our process:

• Incoming material inspection – data only, no favors
  Every batch of steel is tested with an optical emission spectrometer. If the chemistry is out of spec, we reject it immediately. The same standard applies to suppliers we’ve worked with for ten years and new ones alike.
• Random in-process checks – no warning
  On the machining line, our QC staff randomly pick 5–10 pieces every day to check hardness, dimensions, and run magnetic particle inspection. If a problem is found, the whole shift is traced back, and any non-conforming parts are scrapped on the spot.
• 100% final inspection on critical dimensions
  For pin-to-bushing clearance, sealing surface roughness of hydraulic fittings, thread go/no-go gauges — anything that directly affects installation and performance — we check every single part. No suspicious piece is allowed to ship.

Instead of giving you a pile of test reports, we prefer to do one thing first: help you choose the right part and clarify the real need.

Many customers send an inquiry with only a part number or a blurry photo. We don't quote immediately. Instead, we ask a few key questions:

• What working conditions does the excavator mainly operate in? (Mining, earthmoving, or breaking?)
• How did the previous parts fail? (Wear, breakage, or oil leakage?)
• What replacement interval are you expecting? What’s your budget range?

Why do we ask? Because the same part used in different applications requires completely different material selection and treatment. For example, a bushing in earthmoving conditions works fine with standard wear-resistant steel, but mining conditions require carburizing + deep hardening. We never push expensive parts just to close a deal, nor give you the wrong part for a low price.

Our consulting logic is simple: first, we help you determine the most suitable material, hardness, and machining accuracy — then we provide a quote and a QC plan. If you already have drawings or samples, we can even do a free review to check whether the dimension tolerances are reasonable and whether the heat treatment requirements match your actual working conditions.

For you, this means: no wasted money, no unnecessary detours.

Different parts come with different concerns. Here's what we’ve learned from our customers:

Track shoe users: worry about misaligned bolt holes that prevent installation. We re-check the pitch of every track shoe with a dedicated gauge and do a trial assembly before shipment.

Hydraulic part customers: fear seal leakage. Our fittings and valve blocks are pressure-tested at 1.5 times working pressure (up to 45 MPa). If one drop leaks, it doesn't leave the factory.

Tooth buyers: want wear resistance. We run regular bench wear comparison tests. If a batch doesn’t match the life of first-tier domestic brands, it's not shipped.

Hydraulic breaker customers: care about unstable impact force, piston scoring, and housing cracking. Before assembly, every piston and cylinder in our breaker core is 100% NDT inspected (magnetic particle + ultrasonic) to ensure no micro-cracks. After assembly, we put the unit on a test stand and run 20,000 consecutive strikes while monitoring impact pressure and return oil temperature. Many repeat customers report that breakers rebuilt with our parts last at least one-third longer than those using generic parts. We also double-check bolt pre-torque and accumulator nitrogen pressure — if these two points are off, a new hammer will fail within days.

No one is perfect, but we promise: no excuses, fast response.

If you receive parts with quality issues (out-of-tolerance dimensions, insufficient hardness, cracks), just take photos and contact us. We’ll give you a solution within 24 hours — replacement, refund, or repair, however you prefer. At the same time, we'll run an internal 8D analysis to find the root cause and prevent the same problem from happening again.

Not from certificates — from years of real-world experience:

• We’ve supplied second-tier components to multiple domestic excavator OEMs.
• We export year-round to Southeast Asia, Africa, and South America, handling tough working conditions.
• Our team includes at least three QC veterans with over ten years in this industry.

They can tell whether a lathe tool is dull just by looking at the color of the chips — that kind of experience is more reliable than any equipment.

If you're looking for a steady supplier of excavator parts, send us your drawings or samples. We’ll do a free dimensional review and material recommendation. Even if we don't end up working together, at least you’ll know what to watch out for with that batch of parts.

Contact our QC engineers to get a quality control plan for your specific machine model and parts.