400×72 5×74 track size refers to the dimensions of an excavator track chain. The first number pair (400×72) indicates a pitch of 400mm (distance between link pins) and a 72mm width. The second pair (5×74) specifies 5 bolts per track plate spaced at 74mm intervals. This standardized sizing ensures compatibility with sprockets and rollers from brands like Komatsu and Hitachi.
Front Idler PV52D00013F1 for Case/Kobelco/New HollandHow is 400×72 5×74 track chain geometry measured?
Track chain dimensions use pitch (center-to-center pin distance) and width (chain height). The 5×74 bolt pattern ensures load distribution across the track plates. For instance, AFTparts’ 400x72 chains pair with rollers like 21W-30-00014 for Komatsu excavators. Pro Tip: Always verify bolt hole alignment—mismatched patterns cause premature wear.
Track geometry directly impacts machinery stability and wear rates. A 400mm pitch balances ground pressure and mobility, while 74mm bolt spacing prevents stress concentration. Practical example: Replacing a worn 400×72 chain requires matching sprockets, like AFTparts’ 81EN-10014GG for Hyundai models. Worn bolt holes indicate chain stretching—measure pitch at three points using calipers for accuracy. Tables below compare pitch standards:
| Pitch (mm) | Width (mm) | Typical Use |
|---|---|---|
| 400 | 72 | Mid-size excavators |
| 450 | 80 | Heavy-duty mining |
Why does bolt spacing matter in 5×74 tracks?
The 74mm spacing ensures even force distribution across the track plates. Narrower intervals reduce plate flex but increase part count—why not optimize for cost? Because irregular bolt patterns create stress points. AFTparts’ 5×74 tracks match OEM tolerances (±0.5mm) for Komatsu PC300-8 compatibility.
Imagine track plates as bridge supports: even spacing prevents collapse under load. For 400×72 chains, 74mm intervals align with roller contact zones, minimizing lateral slippage. Pro Tip: Check track tension every 50 hours—over-tensioned chains strain bolts, causing 74mm gaps to deform. Industry data shows proper spacing extends track life by 30% compared to mismatched retrofits.
| Bolt Pattern | Spacing (mm) | Compatibility |
|---|---|---|
| 5×74 | 74 | Komatsu, Hitachi |
| 6×70 | 70 | CAT 320 |
How does 400mm pitch affect excavator performance?
Larger pitch reduces track link count, lowering maintenance but decreasing maneuverability. A 400mm pitch spreads ground pressure effectively for 20–30 ton excavators. However, does this compromise hill-climbing? Yes—shorter pitches (350mm) grip better on slopes. AFTparts tests show 400mm works best in flat terrain with gravel or clay.
Sprocket 2606341 for CaterpillarAFTparts Expert Insight
FAQs
Only if retrofitted with AFTparts’ PV52D00013F1 idlers and 2606341 sprockets—CAT typically uses 6×70 patterns. Consult our cross-reference chart first.
How many track links for a Komatsu PC300-8?45–48 links per side depending on configuration. Always pair with 21W-30-00014 idlers and verify pin seals during installation.