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Shoulder Bolts
A comprehensive engineering reference for tooling engineers, die & mould designers, precision machinery specialists and procurement teams — covering shoulder bolt geometry, precision shoulder tolerances, dimensional standards, material grades, surface treatments, bearing and pivot applications, and full documentation requirements.
Shoulder Bolt Types, Engineering Function
& Precision Shoulder Geometry
Stripper Bolt · Pivot Pin · Guide Pin · Liner Bearing Shaft · Socket Head
Definition and Engineering Function
A shoulder bolt (also called a shoulder screw, stripper bolt or socket shoulder screw) is a precision fastener comprising three distinct machined zones: a cylindrical unthreaded shoulder of precise diameter and length, a reduced-diameter threaded shank below the shoulder, and a socket-head or hex-head cap above the shoulder. Unlike standard bolts where the shank and thread are the same or similar diameter, the shoulder bolt's defining feature is that the shoulder diameter is always larger than the thread diameter, creating a precisely dimensioned cylindrical bearing surface that serves as a shaft, pivot pin, guide pin, linear bearing shaft or spacer — while the threaded end anchors the bolt into a tapped hole in the base component.
The engineering value of a shoulder bolt lies entirely in the precision of its shoulder geometry. The shoulder is ground to h6 tolerance (typically −0 to −0.011 mm on a 10 mm shoulder) — the same tolerance class used for precision shaft fits in rolling element bearing housings. This precision enables the shoulder to function as an accurate running clearance, interference or transition fit shaft in mating bored components, providing defined radial location, smooth rotational pivoting, or controlled linear sliding without the play and imprecision of a plain threaded bolt shank.
A shoulder bolt must never be tightened to clamp the shoulder against the mating component. The shoulder length must be equal to or slightly greater than the total thickness of the components through which it passes — so that when the thread is tightened into the tapped base, the shoulder sits proud of the component stack, leaving the head underside clear of the bearing surface. If the shoulder is too short, the head bears down on the top component and prevents the bored component from moving freely on the shoulder. This is the single most common shoulder bolt installation error in die and mould work.
Shoulder Bolt Anatomy — The Four Precision Zones
Shoulder Bolt Types — Engineering Descriptions
| Type | Standard | Head Style | Shoulder Tol. | Material | Primary Application |
|---|---|---|---|---|---|
| Standard Socket Shoulder | ISO 7379 / ASME B18.3 | Socket cap | h6 | Alloy 12.9 / SS | Die & mould, tooling pivots, guides |
| Stripper Bolt | ISO 7379 / die spec | Socket cap | h6 | Alloy 12.9 | Punch press stripper plates |
| Long Shoulder Bolt | ISO 7379 / custom | Socket cap | h6 | Alloy 12.9 / SS | Guide posts, linear slides, transfer dies |
| Wide Shoulder Bolt | Custom to drawing | Socket / hex | h6 / h7 | Alloy / SS | Heavy pivots, large-bore linear bearings |
| Hex Head Shoulder | Custom / DIN var. | External hex | h6 / h9 | Alloy / SS | Construction, structural, heavy machinery |
| SS / Titanium Shoulder | ISO 7379 / custom | Socket cap | h6 | SS 304/316/Ti Gr5 | Food, pharma, aerospace, medical, chemical |
Dimensional Data, Precision Tolerances
& Bore Fit Selection Reference
Shoulder Diameter · Shoulder Length · Thread Size · h6 Tolerance
Shoulder Bolt Dimensions — ISO 7379
| Shoulder Dia. d (mm) | Thread Size | Shoulder h6 Tol. (mm) | Head Dia. D (mm) | Head Height H (mm) | Hex Socket s (mm) | Standard Shoulder Lengths L (mm) |
|---|---|---|---|---|---|---|
| Ø4 | M3 | 0 / −0.008 | 6.5 | 3.3 | 2 | 4, 6, 8, 10, 12, 16 |
| Ø5 | M4 | 0 / −0.008 | 8.5 | 4.2 | 3 | 4, 6, 8, 10, 12, 16, 20 |
| Ø6 | M4 | 0 / −0.008 | 10.0 | 5.0 | 3 | 6, 8, 10, 12, 16, 20, 25 |
| Ø8 | M5 | 0 / −0.009 | 13.0 | 6.0 | 4 | 8, 10, 12, 16, 20, 25, 30 |
| Ø10 | M6 | 0 / −0.009 | 16.0 | 7.0 | 5 | 10, 12, 16, 20, 25, 30, 40 |
| Ø12 | M8 | 0 / −0.011 | 18.0 | 8.0 | 6 | 12, 16, 20, 25, 30, 40, 50 |
| Ø16 | M10 | 0 / −0.011 | 24.0 | 10.0 | 8 | 16, 20, 25, 30, 40, 50, 60 |
| Ø20 | M12 | 0 / −0.013 | 30.0 | 13.0 | 10 | 20, 25, 30, 40, 50, 60, 80 |
| Ø25 | M16 | 0 / −0.013 | 36.0 | 16.0 | 14 | 25, 30, 40, 50, 60, 80, 100 |
ISO 7379:2011. Shoulder diameter tolerance: h6 (negative deviation only — shoulder is always at or below nominal, never above). Thread engagement depth in tapped hole = 1.5× thread diameter minimum. Shoulder length tolerance: ±0.25 mm on standard lengths. Custom shoulder lengths available to 0.05 mm tolerance.
Precision Shoulder Tolerance and Bore Fit Selection
The shoulder bolt's shoulder diameter is ground to h6 tolerance — a negative-deviation shaft tolerance that ensures the shoulder is always at or below the nominal diameter (never oversize). This is paired with a mating bore in the clamped or sliding component to create a defined fit class. The choice of bore tolerance determines the fit class: clearance, transition or interference. For shoulder bolt applications, the mating bore is almost always specified as H7 (a positive-deviation hole tolerance), creating a running clearance fit with the h6 shoulder.
| Nominal Dia. Range | h6 Upper Dev. (µm) | h6 Lower Dev. (µm) | H7 Bore Upper Dev. (µm) | H7 Bore Lower Dev. (µm) | H7/h6 Min Clearance (µm) | H7/h6 Max Clearance (µm) |
|---|---|---|---|---|---|---|
| Ø3–6 mm | 0 | −8 | +12 | 0 | 0 | +20 |
| Ø6–10 mm | 0 | −9 | +15 | 0 | 0 | +24 |
| Ø10–18 mm | 0 | −11 | +18 | 0 | 0 | +29 |
| Ø18–30 mm | 0 | −13 | +21 | 0 | 0 | +34 |
| Ø30–50 mm | 0 | −16 | +25 | 0 | 0 | +41 |
ISO 286-1:2010. H7/h6 fit provides a minimum clearance of 0 µm (no interference) and maximum clearance of approximately 24–41 µm depending on size. This is the standard specification for shoulder bolt pivot and guide pin applications. Bores must be reamed (not drilled) to H7 tolerance for shoulder bolts — drilled holes are not accurate enough.
| Shoulder Dia. (in) | Thread Size | Shoulder Dia. Tol. (in) | Head Dia. (in) | Head Height (in) | Hex Socket (in) | Standard Shoulder Lengths (in) |
|---|---|---|---|---|---|---|
| 3/16" | #10-32 UNF | +0.000 / −0.0003 | 5/16 | 7/32 | 5/64 | 3/8, 1/2, 5/8, 3/4, 1 |
| 1/4" | #10-32 UNF | +0.000 / −0.0003 | 3/8 | 9/32 | 3/32 | 3/8, 1/2, 5/8, 3/4, 1, 1-1/4 |
| 5/16" | 1/4-20 UNC | +0.000 / −0.0004 | 15/32 | 11/32 | 1/8 | 1/2, 5/8, 3/4, 1, 1-1/4, 1-1/2 |
| 3/8" | 5/16-18 UNC | +0.000 / −0.0004 | 9/16 | 13/32 | 5/32 | 1/2, 3/4, 1, 1-1/4, 1-1/2, 2 |
| 1/2" | 3/8-16 UNC | +0.000 / −0.0005 | 3/4 | 17/32 | 3/16 | 3/4, 1, 1-1/4, 1-1/2, 2, 2-1/2 |
| 5/8" | 1/2-13 UNC | +0.000 / −0.0005 | 15/16 | 21/32 | 1/4 | 1, 1-1/4, 1-1/2, 2, 2-1/2, 3 |
| 3/4" | 5/8-11 UNC | +0.000 / −0.0006 | 1-1/8 | 13/16 | 5/16 | 1-1/4, 1-1/2, 2, 2-1/2, 3, 4 |
ASME B18.3-2012. Shoulder diameter tolerance is equivalent to h6. Thread is UNF (fine pitch) for smaller diameters providing better thread engagement in shallow tapped holes. Mating bore tolerance H7 recommended (reamed, not drilled).
L_shoulder ≤ t_total + 0.25 mm // Maximum overhang: ~0.25 mm to ensure head clears bored component top face
t_total = t1 + t2 + … + tn // Sum of all component thicknesses engaged by shoulder (bearing plate, washer, etc.)
// WORKED EXAMPLE: Stripper plate 20 mm + guide bushing flange 2 mm = 22 mm stack
L_shoulder_min = 22.0 mm
L_shoulder_max = 22.0 + 0.25 = 22.25 mm
// Select standard ISO 7379 length: Ø16 shoulder bolt — nearest standard length is 25 mm
// 25 mm > 22.25 mm → TOO LONG — use 20 mm shoulder length + 2 mm shim, or custom 22 mm length
Material Grades, Mechanical Properties
& Surface Treatments
Black Oxide · PVD TiN · Hard Chrome · Passivation · Anodise
| Grade | Standard | Tensile Str. (MPa) | Hardness | Density (g/cm³) | Corrosion | Key Application |
|---|---|---|---|---|---|---|
| Alloy Steel 12.9 | ISO 898-1 | ≥1220 | 39–44 HRC | 7.85 | Low | Die & mould, punch press, precision tooling (default) |
| SS 304 (A2-70) | ISO 3506-1 | ≥700 | ≤220 HV | 7.93 | High | Food, pharma, general outdoor, wet industrial |
| SS 316L (A4-80) | ISO 3506-1 | ≥800 | ≤220 HV | 7.98 | Very High | Offshore, chloride, chemical plant pivots |
| Duplex 2205 | ASTM A182 F51 | ≥620 | ≤310 HB | 7.80 | Very High | Offshore structural pivots, sour service |
| Titanium Gr.5 (Ti-6Al-4V) | ASTM F1472 | ≥895 | 30–36 HRC | 4.43 | Extreme | Aerospace, motorsport, medical, weight-critical |
| Brass (CuZn37) | BS 2872 | ≥370 | ~120 HV | 8.50 | Good | Electrical pivot contacts, marine, decorative |
| Aluminium 7075-T6 | ASTM B211 | ≥503 | ~87 HRB | 2.81 | Moderate | Lightweight tooling, motorsport, UAV structures |
| Nylon PA66 GF30 | ISO 527 | ~180 | ~80 HRR | 1.38 | Excellent | Electrical isolation, lightweight, chemical resist. |
Material Selection Guidance
Alloy steel Grade 12.9 shoulder bolts are the default for die and mould applications, punch press stripper assemblies, precision jigs and fixtures and tooling pivot pins. The high tensile strength (1220 MPa minimum) provides excellent fatigue resistance under cyclic loading, and the hardness range (39–44 HRC) ensures the shoulder surface resists fretting and wear during millions of press cycles. Grade 12.9 shoulder bolts are supplied with black oxide finish for die and mould use — the black oxide provides light corrosion protection and retains cutting oil, which lubricates the shoulder during cycling. Never use Grade 12.9 shoulder bolts in structural applications or on live loads without a design calculation — Grade 12.9 is susceptible to hydrogen embrittlement under sustained tensile stress in the presence of hydrogen-producing environments.
Stainless steel shoulder bolts operating in stainless steel bores have a very high galling (cold welding) tendency — the combination of the long contact length of the shoulder in the bore, the high contact stress during sliding, and the identical alloy families creates ideal conditions for adhesive wear and galling seizure. Anti-galling measures are mandatory for all SS shoulder bolt – SS bore combinations: apply MoS₂ paste, PTFE dry film lubricant or Xylan coating to the shoulder before assembly. Alternatively, specify a SS 316L shoulder bolt in a SS 304 bore (dissimilar grades — reduces galling tendency) or use a PTFE-lined bore insert. Never assemble bare SS shoulder bolt into a bare SS bore without lubricant.
Titanium Grade 5 (Ti-6Al-4V) shoulder bolts provide a 43% weight reduction over equivalent alloy steel shoulder bolts while maintaining comparable tensile strength (895 MPa vs 1220 MPa for Grade 12.9). They are used in aerospace structural pivots, racing car suspension pivot pins, high-performance bicycle components and medical device articulating joints where weight reduction is a primary design objective. Titanium shoulder bolts must always be specified with an anodised or PVD-coated shoulder — bare titanium-to-metal contact produces titanium oxide debris (galling) and the shoulder surface must be protected.
| Finish | Standard / Spec | Layer Thickness (µm) | Hardness (HV) | Dimensional Impact | Notes & Best Application |
|---|---|---|---|---|---|
| Black oxide + oil | MIL-DTL-13924 | 0.5–2 | No change | Negligible (<1 µm) | Standard for Grade 12.9 die & mould; retains oil; zero bore clearance impact |
| Phosphate + oil | MIL-DTL-16232 | 5–15 | No change | 2–5 µm per side | Consistent K-factor; mild corrosion protection; slight clearance reduction |
| Hard chrome plate | AMS 2460 / QQ-C-320 | 2–25 | 900–1100 | Adds to shoulder dia. | Wear and corrosion resistance; must specify "grind after plate" to maintain h6 |
| PVD TiN (gold) | Proprietary / ASTM B571 | 2–5 | 2000–2500 | 1–2 µm per side | Very high hardness; low friction (μ=0.4); minimal bore impact; die & mould high-cycle |
| PVD TiCN (grey) | Proprietary | 2–5 | 3000–3500 | 1–2 µm per side | Higher hardness than TiN; excellent wear; minimal dimensional addition |
| DLC (diamond-like carbon) | Proprietary | 1–3 | 1500–3500 | <1 µm per side | Ultra-low friction (μ=0.05–0.15); near-zero dimensional addition; high-speed pivots |
| SS passivation | ASTM A380 | N/A (passive) | No change | None | SS shoulder bolts; restores passive film post-machining; no dimensional change |
| Anodise (Type III) | MIL-A-8625 Type III | 12–25 | 400–600 | Grows into surface | Aluminium shoulder bolts; hard anodise for wear resistance; slight bore impact |
| MoS₂ dry film | MIL-L-23398 | 5–15 | N/A | 3–8 µm per side | Anti-galling on SS; low friction; food-grade grades available |
| PTFE / Xylan | Whitford spec. | 15–30 | N/A | 8–15 µm per side | Anti-galling SS; very low friction; verify bore clearance after coating |
CRITICAL: Any coating that adds material to the shoulder diameter reduces the clearance between shoulder and bore. PVD and DLC coatings add 1–2 µm per side (negligible). Hard chrome adds significantly more and requires post-plate grinding to restore h6. Always verify the post-coat shoulder diameter against the bore H7 tolerance to confirm the fit class is maintained.
Unlike standard fasteners where coating thickness on the hex flats is the critical dimension, for shoulder bolts the coating thickness on the precision shoulder is the critical dimension. A shoulder specified at Ø10 h6 (9.991–10.000 mm) with a PVD TiN coating of 3 µm per face becomes Ø10.006 mm after coating — now exceeding the h6 upper limit and potentially producing an interference fit with the H7 bore. Specify coating thickness explicitly on the drawing and confirm: post-coat shoulder OD = nominal − lower h6 deviation + 2×coating = must remain ≤ nominal diameter for all coating types except those requiring post-coat grinding.
Inspection, QC Protocols, Applications
& Export Documentation
Die & Mould · Punch Press · Linear Bearing · Pivot Pin · Aerospace
Inspection and Quality Control
The shoulder diameter is the primary functional dimension of a shoulder bolt and must be measured with calibrated instrumentation to confirm h6 compliance. A bench micrometer (resolution 0.001 mm or better) or calibrated precision bore gauge measured at three axial positions and two perpendicular angular positions is required to verify both the size and form (roundness and cylindricity) of the shoulder. A shoulder that measures within h6 at one point but is out-of-round may create binding or uneven bearing in the mating bore. For precision applications (h6 / H7 running fit), cylindricity must be verified in addition to diameter: maximum cylindricity error = h6 tolerance / 2 = approximately 4–6 µm for Ø6–25 mm shoulders.
The shoulder surface roughness must be measured by profilometer (contact stylus or optical) and confirmed to be Ra ≤ 0.4 µm (N5 finish class) as ground. A rougher shoulder surface increases the friction coefficient in the bore, causes fretting wear at higher cycle rates and reduces the achievable life of the shoulder-bore interface. Runout of the shoulder relative to the thread axis must be verified on a V-block or between centres — a shoulder bolt with more than 0.01 mm TIR (total indicator runout) between shoulder and thread axis will impose a bending moment on the tapped hole with each assembly cycle, progressively damaging the thread.
Thread gauging per Go/No-Go (ISO 1502 or ASME B1.2) is performed on each batch. Shank-to-shoulder concentricity is also verified — the thread axis must be coaxial with the shoulder axis within the runout tolerance specified. A non-concentric thread causes the shoulder to bear unevenly in the bore, creating localised contact stress on one side that accelerates fretting and wear of the shoulder surface.
For Grade 12.9 shoulder bolts, Rockwell hardness (HRC) is measured on the bolt head face (per ISO 898-1 procedure) and compared against the specified range (39–44 HRC). Hardness below 39 HRC indicates insufficient heat treatment and reduced fatigue resistance. Hardness above 44 HRC indicates potential hydrogen embrittlement susceptibility and increased notch sensitivity. Both conditions require batch rejection and re-heat treatment or scrap.
Applications by Industry
Shoulder bolts (stripper bolts) are the standard fastener in progressive die, transfer die and compound die assemblies for punch press operations. In a typical progressive die, Grade 12.9 alloy steel shoulder bolts pass through the stripper plate (a floating plate that strips the material from the punch after each press stroke), with heavy-duty die springs over the shoulder between the stripper plate underside and the die holder. The shoulder length precisely limits the maximum stroke of the stripper plate, and the precision h6/H7 fit guides the stripper plate parallel to the punch direction — preventing angular misalignment that would cause punch-to-die clearance variation and premature wear. Typical press cycle rates of 100–400 strokes per minute mean a shoulder bolt in a production die may complete 100 million+ cycles over its service life — fatigue life is the design-limiting factor.
Shoulder bolts serve as precision pivot pins and guide posts throughout precision machinery: indexing turret pivot pins, dial plate rotational pivots, cam follower mounting shafts, link and lever pivot connections, and guide post assemblies in transfer tooling. The h6/H7 fit provides accurate radial location and smooth rotation with minimal play, maintaining the geometric accuracy of the mechanism. For high-cycle pivot applications (millions of cycles), PVD TiN or DLC-coated shoulder bolts with lubricant reservoirs in the bore are specified to achieve the required service life without shoulder wear.
Standard shoulder bolts are commonly used as short linear bearing shafts where a bored component must translate (slide) along the shoulder axis. A linear bearing assembly on a shoulder bolt provides defined radial location, a controlled clearance fit per H7/h6, and positive axial stop at the head and shoulder step. Applications include slide guide pins in injection moulding tools, ejector pin retainer plate guide assemblies, pneumatic slide actuator guide shafts and precision micropositioner guide pins. For high-speed linear sliding, DLC-coated shoulders with PTFE-impregnated bore bushings provide the lowest friction and longest service life.
Titanium Grade 5 shoulder bolts are used as pivot pins in aerospace control surface hinges, engine mount links, landing gear latch pins, racing car suspension rocker arm pivots, and racing bicycle derailleur pivots. The weight saving over alloy steel (57% weight reduction) at equivalent or near-equivalent strength is the driver for specification. All titanium shoulder bolts in structural aerospace applications must be supplied with AS9100D quality certification, dimensional inspection CMM report and material certification per AMS 4928 (Ti-6Al-4V bar stock). Anodised or PVD-coated shoulder to prevent galling in aluminium bores.
Stainless steel 316L shoulder bolts with passivation (ASTM A380) or electropolish (ASTM A967) are used as pivot and guide pins in food processing equipment, pharmaceutical packaging machinery, cleanroom robot arm joints and semiconductor handling pivots. The smooth, crevice-free shoulder surface after electropolishing satisfies 3-A Sanitary Standards for food-contact applications. Anti-galling PTFE or MoS₂ treatment is mandatory for SS shoulder bolt – SS bore assemblies. Nylon PA66 or PVDF shoulder bolts are specified where metal-free requirements are absolute (direct food-contact, pharmaceutical dispensing machinery).
Medical-grade shoulder bolts in SS 316L or titanium Grade 5 are used as articulating joint pins in surgical instruments (haemostatic forceps, rongeurs, scissors, needle holders), orthopaedic implant locking mechanisms, endoscopic tool pivot assemblies and diagnostic equipment linkages. Medical shoulder bolts must meet ISO 13485:2016 quality management requirements and ASTM F899 (SS surgical instruments) or ASTM F136 (titanium surgical instruments) material standards. Electropolish to Ra ≤ 0.4 µm is mandatory for all implantable applications. CMM dimensional report and 100% inspection are standard for medical device production runs.
Export Packaging and Preservation
- Shoulder bolts packed individually in segmented foam trays or in poly bags separated by foam dividers — shoulder surfaces must not contact each other or other metal surfaces during transport; even minor scratches on the precision shoulder destroy the h6 tolerance and render the bolt non-functional
- VCI (Volatile Corrosion Inhibitor) paper wrapping for bare and black-oxide alloy steel shoulder bolts for sea freight or long-term storage
- Each bolt batch labelled with: PO number, shoulder diameter, shoulder length, thread size, standard (ISO 7379 / ASME B18.3), material grade, surface finish, h6 tolerance confirmation, heat/lot number and quantity
- Bags or trays in double-wall corrugated carton with foam void fill — no loose packing
- Cartons on ISPM-15 heat-treated timber pallets with stretch wrap and steel strapping for export
- Dimensional inspection report, surface roughness report, thread gauge certificate, hardness certificate (for Grade 12.9) and all project documents in waterproof sealed envelope attached to outer carton
| # | Document | Standard / Reference | Minimum Requirement |
|---|---|---|---|
| 01 | Material Test Certificate (MTC) | EN 10204 3.1 / 3.2 | 3.2 for aerospace, medical and offshore applications |
| 02 | Dimensional Inspection Report (CMM) | ISO 7379 / ASME B18.3 | Shoulder diameter, shoulder length, head dimensions; AQL 1.0 per ISO 2859 |
| 03 | Shoulder Diameter CMM / Micrometer Report | ISO 286-1 h6 | Mandatory measured characteristic; 3-point axial + 2 angular measurements per bolt (sampled) |
| 04 | Surface Roughness Report | ISO 4287 / ASME B46.1 | Ra ≤ 0.4 µm on shoulder surface; profilometer trace required for precision applications |
| 05 | Runout / Concentricity Report | ISO 1101 | Shoulder TIR vs thread axis ≤ 0.01 mm; required for high-precision pivot and guide applications |
| 06 | Thread Gauge Certificate | ISO 1502 / ASME B1.2 | Go/No-Go per heat lot; mandatory |
| 07 | Hardness Test Report | ISO 6508 (HRC) / ISO 6507 | Mandatory for Grade 12.9; range 39–44 HRC confirmed |
| 08 | PMI Report (XRF / OES) | Project specification | 100% of SS, titanium, duplex and exotic grade shoulder bolts |
| 09 | Heat Treatment Certificate | ISO 898-1 / AMS spec | Required for Grade 12.9 and Titanium Gr.5 shoulder bolts |
| 10 | Surface Coating Certificate | MIL-DTL-13924 / AMS 2460 | Required for all coated finishes; post-coat shoulder OD confirmed within h6 |
| 11 | ISO 9001 / AS9100D Manufacturer Certificate | ISO 9001:2015 / AS9100D | ISO 9001 standard; AS9100D for aerospace applications |
| 12 | ISPM-15 Phytosanitary Certificate | IPPC / FAO | All wood packing for international export |
RR Hydraulics manufactures and exports shoulder bolts (shoulder screws / stripper bolts) in all types — standard socket head (ISO 7379), stripper bolt, long shoulder, wide shoulder, hex head and custom to drawing — in alloy steel Grade 12.9, stainless steel 304/316L, duplex 2205, titanium Grade 5, brass and aluminium. Precision h6 ground shoulder as standard. Custom shoulder diameters and lengths to ±0.01 mm. Surface finishes: black oxide, PVD TiN, DLC, hard chrome (grind after plate), passivation, electropolish, MoS₂ dry film. Full EN 10204 3.1/3.2 MTC, CMM dimensional reports, surface roughness and hardness certificates. 48-hour express dispatch on standard in-stock sizes.