Selecting a hardness tester starts with the indentation scale your drawing or QA procedure already names — Rockwell, Vickers, Brinell, Leeb, Shore, or Webster — because every other spec (load, indenter, dwell, sample geometry) flows from that single choice. DirectIndustry's June 2026 buying guide lists 12 manufacturers and 28 electric models, with Vickers units spanning 0.001-120 kgf test loads and Rockwell bench testers covering the conventional 10-150 kgf range [S1].
Across the four main scale families, load range alone separates most candidates: bench Vickers (typically 0.001-120 kgf, useful for microhardness and case-depth work), bench Rockwell (10-150 kgf for production-line metals), Brinell (62.5-3000 kgf for castings and forgings), and portable Leeb (no fixed test force — the impact body carries its own spring load and is rated for parts too large to bring to a bench). The decision tree is dominated by sample size, required scale, and whether the part is movable.
Rockwell Bench Testers: The Production Default
Rockwell remains the workhorse scale for heat-treated steels, tool steels, and case-hardened components, with the standard 10-150 kgf load window appearing on units such as the Laizhou Weiyi HR-150B and the motorised HRD-150B [S1]. Both share a 400 mm useful test height and 140 kg net weight, making them a true bench format rather than portable gear. The HRD-150B variant adds electric loading with electronic control for repeatable dwell cycles, while the HR-150B keeps a mechanical lever and dead-weight stack for lower cost and simpler audit traceability.
Engineers who already cite ASTM E18 or ISO 6508 in their inspection plan are essentially locked into Rockwell or Superficial Rockwell geometry — diamond Brale, 1/16 in ball, or tungsten carbide ball indenter with a 10-15 s dwell. If the QA document calls for HRC 58-62 on a through-hardened H13 die, a 150 kgf bench Rockwell is the cheapest credible path. If the same document also calls for HV 0.3 case depth, you need a Vickers bench alongside, not a Rockwell-only machine.
Vickers and Microhardness: Low-Load Precision
Full-scale Vickers testers now commonly span 0.001-120 kgf in a single frame, with the AFFRI WIKI 90 CNC offering 0.001-120 kgf at 145 mm useful height and 160 mm useful width, plus fully automatic multi-indentation pattern execution for case-depth traverses [S1]. That same 0.001 kgf lower bound is what defines the microhardness regime (HV 0.001 to HV 1), so a buyer needing HV 0.3 nitride-layer measurement must verify the 0.001 kgf range is real and not a marketing rounding of 0.01 kgf.
Selection criteria inside the Vickers family split into three: optical vs. depth-sensing measurement, manual vs. CNC stage, and macro-Vickers (1-120 kgf) vs. micro-Vickers (0.001-1 kgf) load coverage. A small heat-treatment lab that only runs HRC and HRA can skip Vickers entirely; a tier-1 automotive case-depth line cannot. Compliance-wise, look for ISO 6507 and ASTM E384 cited explicitly in the manual, not just generic "ASTM/ISO conformance."
Brinell, Leeb, and Portable Methods
Brinell test loads of 3000 kgf (10 mm ball, 3000 kgf, HBW 10/3000) are the only credible option for coarse-grained cast irons, forged steel rolls, and large forgings where Rockwell indent spacing would fall below the indenter-to-edge rule. Universal machines such as the AFFRI LD3000AX cover 1-3000 kgf in one frame at 300 mm useful height, allowing Brinell, Rockwell, and Superficial Rockwell on the same sample without re-fixturing [S1]. The trade-off is floor load: 3000 kgf test force needs a 1000+ kg floor-rated bench, which rules out most portable use.
Portable Leeb testers (also called UCI / dynamic hardness) decouple from bench constraints by using a spring-loaded impact body and reporting hardness in HL units, with typical conversion ranges covering 200-950 HL across steel, stainless, and tool-steel conversion tables. They are the right answer when the part weighs hundreds of kilograms, has already been installed, or cannot be cut into a coupon. Direct comparison of Leeb readings to bench HRC requires the OEM's conversion table for the exact material family — substituting one supplier's table for another is the most common field-error I see. For buyers comparing portable options, ultrasonic thickness gauge selection shares the same "verify the material conversion table before quoting accuracy" rule.
Scratch and Coating Hardness: Niche but Spec-Driven
Scratch hardness testers occupy a different category entirely — they measure coating adhesion and mar resistance, not bulk material hardness. ERICHSEN's LINEARTESTER 249 and 413 use normal loads of 0.5-40 N and 0.001-1.02 kgf respectively, with linear scribe or to-and-fro abrasion modes under ASTM/ISO scratch standards [S1]. These are specified when QA documents cite coating hardness, pencil hardness, or cross-cut adhesion per ISO 15184 / ASTM D3363 — not when the document cites HRC or HV.
If your part is a coated stamping, painted panel, or PVD tool insert, a scratch/coating tester earns its bench space. If the part is a bare heat-treated steel shaft, the scratch tester is irrelevant and a Rockwell/Vickers machine is what the drawing actually calls for. The cheaper path is to identify which standard the customer's print references first, then match the scale — not the other way around.
Who Should NOT Pick a Bench Rockwell
Bench Rockwell is the wrong default in three common cases: small case-hardened parts below 0.5 mm case depth (need micro-Vickers, not HRC, because HRC indents average across the case), thin sheet below 1 mm (need Superficial Rockwell HR15N/HR30N or HR45N to avoid anvil dent), and in-field inspection of installed equipment (need a Leeb or UCI portable). A buyer who specifies a 150 kgf bench Rockwell for any of those three will either fail the test method or produce non-convergent data, regardless of how precise the machine is. [S2]
Another common over-spec is buying a CNC Vickers for routine HRC production checks. CNC Vickers pays back when the test plan includes multi-indent case-depth traverses or automatic pattern generation; for 10 indentations per shift of HRC-only work, the HR-150B at roughly a third the price produces identical release data.
Selection Gate Checklist
Before comparing prices, lock down four gate values: (1) the scale called out in the QA document (HRC, HRB, HV, HBW, HL, Shore A/D) — these are not interchangeable; (2) minimum and maximum test load, including any micro-load requirements; (3) maximum sample height and throat depth — a 400 mm useful height is fine for shafts, useless for gearbox housings; and (4) standard reference — ASTM E18, E10, E384, E110, ISO 6506, 6507, 6508, or ASTM A956 for Leeb. DirectIndustry's June 2026 listing shows 12 electric manufacturers and 28 products, so once those four gates are pinned, the shortlist usually collapses to two or three candidates [S1].
Two secondary gates that often decide the final pick: indenter consumable cost and certification traceability. Diamond indenters for Rockwell and Vickers cannot be re-sharpened; budget roughly $800-2500 for a replacement Brale or Vickers pyramid. Calibration blocks should be traceable to NIST or equivalent national body — suppliers such as Beijing TIME High Technology, Sinowon Innovation Metrology, and the European OEMs (AFFRI, ERICHSEN) all publish traceable block part numbers against their testers [S2][S4].
Manufacturer Landscape and Sourcing
The current sourcing map splits cleanly between European precision OEMs (AFFRI, ERICHSEN — typically higher price, full ISO 6507/6508/6506 traceability) and Chinese volume suppliers (Beijing TIME, Sinowon, Laizhou Weiyi — lower cost, 15-day off-season lead time per Sinowon's 2026 listing, LC/T/T payment terms) [S4]. For a buyer in a tier-1 automotive or aerospace audit chain, the European supplier usually wins on documentation; for a job-shop running 50-200 HRC checks a day, the Chinese bench Rockwell at 140 kg frame weight covers the duty at a fraction of the cost.
For buyers cross-referencing portable methods, ultrasonic thickness gauge price and cost guide covers the same China-vs-EU cost delta on a related NDT instrument family. Final step: verify the chosen tester carries a recent (within 12 months) traceable calibration certificate for the specific scale you will run, not a generic "factory certificate" — that single document is what fails most hardness-tester audits.
Detailed specification references: deadweight tester, and loop tester.