Sourcing HGR20 linear rails from inconsistent suppliers leads to premature brinelling and undocumented hardness. This solution pairs our 58-62 HRC induction-hardened HGR20 rail with matched preload classes and per-batch SGS material reports, so your CNC axes keep geometry under heavy interrupted cuts.
Procurement teams specifying a 20 mm linear guideway for CNC machine tools keep hitting the same three failures. First, rails quoted as HGR20-compatible arrive with surface hardness far below the spec, so raceways brinell within months under interrupted cuts. Second, suppliers cannot produce per-batch material reports, so you cannot close the loop when your own QC rejects a batch. Third, unmatched rail-and-carriage pairs from mixed sources lose preload, and axis rigidity drifts until the machine fails a geometry re-check.
Dongfeng manufactures the HGR series as a matched rail-and-carriage system. The rail body is high-carbon steel induction hardened to 58-62 HRC with controlled case depth, then ground in a single clamping so mounting surfaces and raceway geometry stay consistent. The four-row ball circuit (HGH/HGW carriages) distributes load across four contact lines, which is what keeps the axis rigid under heavy interrupted cuts.
Who / what: a mid-size CNC router builder sourced HGR20 rail and HGH20CA carriages for the X-axis of a 2.5 m gantry mill. Problem: their previous rails softened near the mounting holes after 14 months and the gantry lost 0.02 mm over the travel.
Where the numbers come from: the builder's own semi-annual machine geometry audit records, cross-checked against our batch SGS hardness reports filed in their incoming inspection.
Source: customer engineering correspondence and audit records shared during reorders.
Who / what: a cutting-table OEM operating 30+ machines originally used round-shaft rails, then moved the Y-axis to HGR20 after slag contamination repeatedly seized open bearing blocks. Problem: sealed four-row carriages were needed without widening the machine base.
Where the numbers come from: the OEM's spare-parts consumption ledger, compared across two production years after the retrofit.
Source: OEM service department consumption records, verified at repeat ordering.
★★★★★
Purchasing via Alibaba RFQ for a retrofit program on 5-axis routers.
"Hardness reports arrived inside the shipment crate, matched to the batch codes on the rails. We stopped re-testing every rail in-house."
Source type: buyer follow-up email thread with purchasing department.
★★★★☆
Direct factory order for a machine-rebuild division that standardizes on 20 mm profile rails.
"Preload classes matched what our drawings asked for, and the carriage bodies bolted onto existing HGR20 footprints without shimming."
Source type: annual supplier scorecard completed by the OEM's quality team.
★★★★★
Sourced through our trade-assurance store for a short-lead emergency replacement.
"Cut-to-length 2.8 m rails with end machining shipped in 12 days, and geometry held on the first try-back."
Source type: post-delivery review on the buyer's trade platform order.
Buyers should request the current certificate copies and batch test reports with their quotation; we supply them as standard attachments.
Direct factory supply with OEM/ODM capability supports both volume procurement and custom engineering projects, including cut-to-length rails, non-standard drilling patterns and matched carriage pairs.
HGR Series linear guideway rails feature a 58–62 HRC induction-hardened surface and four-row ball circuit geometry, giving CNC machine tool builders the rigidity and load capacity needed under heavy interrupted cuts.
HGR45 heavy-duty linear guideway rail (45 mm width) with 45# high-carbon steel body induction-hardened to 58–62 HRC and 2.5 mm case depth. Paired with HGW45CA carriage delivers 62.8 kN dynamic and 112 kN static load — engineered for injection molding machines, heavy gantry welders, and large-format CNC routers.
HGH Series flange-type carriage blocks run on HGR rails via a four-row ball recirculation circuit, with a self-aligning angular tolerance of ±0.5° that absorbs minor rail misalignment — suited for retrofit builds and replacement sourcing on CNC and automation frames.
HGW Series wide-body flange-type carriage blocks feature a 20–30% wider mounting footprint than standard HGH carriages, delivering 28.4 kN dynamic load capacity and triple-seal contamination defense for heavy gantry CNC mills, inverted vertical axes, and high-moment-load automation frames.
Z0 is internal clearance, Z1 is light preload and Z2 is medium preload. Higher preload increases rigidity for heavy or interrupted cutting but also raises running temperature; most CNC feed axes order Z1, while heavily loaded gantry axes specify Z2.
Yes when the original rail follows the standard HGR20 mounting pattern. We confirm bolt pitch, rail width and end distances against your old rail before production; send us the old rail's dimensions and we match them.
Every production batch ships with SGS-certified material test reports covering composition, surface hardness (58-62 HRC) and dimensional accuracy, so incoming inspection can file them directly.
Standard lengths run to 4 m, and we cut to length with end-machined joints for splicing longer axes. Non-standard hole patterns and matched carriage sets are available on request.
Rails and carriages are matched at the factory as pairs. Mixing carriages from different batches or brands can lose preload; ordering them as a matched set keeps the contact geometry consistent.
