C17200

🌐JIS and international equivalents

“Close” means composition or properties are not exactly the same. Before substituting, check the values in each standard.

📄Related specifications (AMS, ASTM etc.)

Specifications called up on purchase orders and drawings. AMS are SAE aerospace material specifications, split by product form (bar, plate, forging), melting practice and heat treatment. Standard texts are paid, so only titles and scopes checked on the publishers’ public pages are shown.

All ASTM standards on Kezuriba: ASTM standards quick reference.

✈Main aerospace uses (as stated in the sources)

• Materion lists Alloy 25 (C17200) as a high-strength material for static and dynamic bushings and bearings in landing gear^[30]
• Materion's Alloy 25 tube datasheet lists aircraft bushings and bearings as typical applications^[6]
• NGK Berylco's catalog lists aerospace and defense among the markets for beryllium copper (not a statement of applications limited to C17200)^[2][12]

💪Mechanical properties

“Reference” values are not specified minimums from the standard but figures published by makers and others.

1 MPa ≈ 145 psi (0.145 ksi). Hardness conversion · unit converter

🔧Machinability notes (as stated in the sources)

• Materion: beryllium copper in any form is easily machined with high-speed steel and carbide tools. Recommended are the general-purpose carbide grade C-2 and high-speed steels M1, M2, T1 and T2. Tool life is very good^[7]
• Materion: aging (precipitation hardening) shrinks the material by about 0.5% by volume, so parts needing dimensional accuracy should be finished after heat treatment. Because machinability is good, buying aged material and machining it as is is recommended (aged long lengths may not be available for rod and bar under 7/16in)^[7]
• Materion: The A and H tempers (before aging) tend to produce long, stringy, tough chips, so use a chip breaker. AT and HT (after aging) and leaded C17300 break the chips up and are easier to handle^[7]
• Materion: If the feed is too small (below 0.005 in/rev ≈ 0.13 mm/rev), the material work-hardens, machinability drops and tool wear increases (hardening is smaller in AT and HT). Use a fairly large positive rake angle and avoid 0° or negative rake. Drills and reamers also work-harden if the cutting edge rubs or the feed is set too low^[7]
• Materion turning recommendations (Alloy 25, M25, 165; carbide C-2; feed 0.010–0.020 in/rev ≈ 0.25–0.51 mm/rev): A 1500–1800 ft/min (about 457–549 m/min), H 1200–1500 ft/min (about 366–457 m/min), AT and HT 900–1200 ft/min (about 274–366 m/min). With T-1 high-speed steel, AT and HT 200–300 ft/min (about 61–91 m/min). Reduce by 25% when machining dry^[7]
• Materion's other recommendations (Alloy 25, AT and HT): drilling 100–300 ft/min (about 30–91 m/min) at 0.002–0.009 in/rev (about 0.05–0.23 mm/rev); tapping 15–25 ft/min (about 4.6–7.6 m/min); reaming 50–200 ft/min (about 15–61 m/min); carbide end mills 375–500 ft/min (about 114–152 m/min) at 0.001–0.003 in/tooth (about 0.025–0.076 mm/tooth). If drills chip in the hardest tempers, use a brass-point grind (helix angle reduced to about 5°)^[7]
• Materion: Cutting fluid is recommended for all machining operations (chemical emulsions, water-soluble oils, or mineral oil mixed with lard oil). Sulfurized oils cause discoloration unless washed off promptly. An active cutting oil is recommended for tapping^[7]
• [Safety] Materion: In solid form it poses no special health risk, but inhaling dust, fume or mist containing beryllium can cause serious lung disease in some people. Turning, milling, drilling, tapping, reaming and sawing produce large chips (over 10 µm), so the inhalation concern is low. Grinding, polishing, lapping, honing, buffing, abrasive cutoff, blasting, EDM, coolant management and ventilation-system maintenance, however, can create an inhalation hazard; use local exhaust ventilation, wet methods, enclosure and housekeeping, and respiratory protection where needed^[7]
• [Safety] Materion: Grinding coolant should be filtered because fine particles that build up can dry out and become airborne. Beryllium has been detected in the air above EDM working fluid, so ventilation is required, and compressed air must not be used to clean the equipment^[7]
• [Safety] NGK Berylco: Solid products pose no health risk, and general handling, pressing, most machining and heat treatment are low risk. When dry grinding, polishing, EDM, melting or welding produces dust or fume, there is an inhalation hazard (chronic beryllium disease), and exhaust and filtration must keep exposure below the EU occupational exposure limit of 0.6 µg/m³ (inhalable fraction, 8-hour time-weighted average; EU Directive 2019/983). The UK recommended value is 2 µg/m³^[2]
• [Safety] US OSHA beryllium standard (29 CFR 1910.1024): the permissible exposure limit (PEL) is 0.2 µg/m³ as an 8-hour time-weighted average, the short-term exposure limit (STEL) is 2.0 µg/m³ over 15 minutes, and the action level is 0.1 µg/m³. Sensitization to beryllium can lead to chronic beryllium disease, and beryllium can also cause lung cancer. Copper alloys are the most common use, and machinists and welders are listed among the occupations with possible exposure^[13][14]
• [Safety] NIOSH treats beryllium as a potential occupational carcinogen (Ca) and sets the IDLH at 4 mg/m³ (as Be)^[15]
• [Safety] Under the Japanese Ministry of Health, Labour and Welfare's work environment evaluation standards, the control concentration for beryllium and its compounds is 0.001 mg/m³ as beryllium (= 1 µg/m³). The GHS model SDS on the ministry's Safety Information Site (revised 2006) classifies beryllium as a Class 1 substance and specially controlled substance under the Ordinance on Prevention of Hazards Due to Specified Chemical Substances^[16][17]
• Free-machining relative: C17300, with lead added (Materion M25, NGK Berylco 33/25, EN CW102C), has the same mechanical properties as C17200 and is used when finely broken chips are wanted (Materion says it is commonly run in the H and 1/2H tempers on automatic lathes)^[7][2]