products
Cut wire (CW)
CW LINE · 100 % SOLID
Metallic abrasive for shot peening of critical fatigue-loaded components
CYM Materiales supplies cut wire shot (CW), a metallic abrasive manufactured from drawn carbon steel wire cut into cylinders of controlled length and diameter, available in eight grades from CW 17 to CW 47. It is the reference media for shot peening of critical fatigue-loaded components: gears, helical springs, leaf springs, blades, bearing seats and aerospace parts where fatigue resistance and process repeatability are contractual requirements.
Unlike cast spherical shot, cut wire shot has 100 % solid grains —with no internal porosity or casting inclusions—, resulting in higher compaction power on the treated surface, more uniform generation of residual compressive stresses and a media life several times longer than equivalent cast shot. Its controlled drawn-wire microstructure also noticeably reduces dust generation and premature wear on the blast machine components.
CYM Materiales supplies the CW line under the world-reference aerospace and industrial standards —AMS 2431-3, AMS 2431-8, AMS-S-13165, SAE J441 and VDFI 8001—, in four standard hardness levels between 56 and 65 HRC and in four rounding grades: CW (as-cut cylindrical), CCW (conditioned), DCCW (double conditioned) and SCCW (spherically conditioned), allowing process tuning from maximum Almen intensity shot peening to peening finishes on parts with delicate geometry.
If your application requires a specific recommendation —including certified processes under aerospace or automotive standards—, our technical team advises on the most suitable diameter, hardness and rounding grade.
APPLICATIONS
Uses and processes with cut wire shot
Cut wire shot is used almost exclusively for shot peening, a controlled blasting process whose objective is not cleaning or surface preparation but the induction of residual compressive stresses on the part surface to increase fatigue resistance, delay crack propagation and extend the service life of mechanical components subjected to cyclic loads. It is used both in centrifugal wheel machines with Magna Valve and abrasive mass control, and in compressed air systems with indexed nozzles and CNC manipulators, and the choice of grade, hardness and rounding depends on the target Almen intensity and the applicable contractual specifications.
SHOT PEENING BY CENTRIFUGAL WHEEL
- Compatible with CYM Materiales SAT satellite machines for shot peening of gears, pinions, ring gears and transmission discs
- Suited to continuous shot peening of helical springs and stress peening of leaf springs under tension
- Grades CW 17 to CW 32 (0.4–0.8 mm) for medium Almen intensities on mechanical components
- Grades CW 35 to CW 47 (0.9–1.2 mm) for high Almen intensities on demanding parts
- Longer media life than equivalent cast spherical shot, with lower wear on wheels and nozzles
- Delivers a stable operating mix with increasing rounding during the first cycles
SHOT PEENING BY COMPRESSED AIR
- Suited to cabinets and work cells with CNC manipulators for localised shot peening of gears, pinions, ring gears and transmission discs
- Recommended for bearing seats, stress concentration areas and delicate geometries
- Compatible with Magna Valve automatic control and in-line Almen intensity monitoring
- Complies with aerospace standards AMS 2431-3, AMS 2431-8, AMS-S-13165, GE-Spec and BAC-Spec
- Critical applications: turbine blades, landing gears, aeronautical structural components
- Available in SCCW (spherically conditioned) rounding grade for processes with strict geometric tolerance
TECHNICAL SPECIFICATIONS
Manufacturing standards and composition
Cut wire shot is manufactured from drawn carbon steel wire, cut into cylinders of controlled length and diameter, and subsequently heat-treated to reach the specified hardness. Unlike cast spherical shot —obtained by pouring and controlled cooling—, cut wire derives from a dense, porosity-free wire, resulting in 100 % solid grains with no inclusions or internal microvoids. CYM Materiales supplies the CW line under the world-reference aerospace and industrial standards:
| Standar | Scope | Application |
|---|---|---|
| AMS 2431-3 | Aerospace — United States | Cut wire shot peening media (carbon steel) |
| AMS 2431-8 | Aerospace — United States | Cut wire shot peening media (high hardness) |
| AMS-S-13165 | Aerospace — US defense | Shot peening on aeronautical components |
| SAE J441 | Automotive and industrial | Cut wire shot — general specification |
| VDFI 8001 | Industrial — Germany (VDFI) | Cut wire shot — quality and delivery |
| GE-Spec | Manufacturer-specific | General Electric contractual processes |
| BAC-Spec | Manufacturer-specific | Boeing Aircraft contractual processes |
The base steel is drawn carbon steel of controlled composition, in accordance with the chemical and mechanical requirements of each applicable standard. The specific chemical composition varies by grade and selected standard; CYM Materiales can issue a per-lot quality certificate on request, listing chemical analysis, Vickers hardness, cut dimensions and rounding grade. Other hardness levels and standards (including certified aerospace and automotive processes) are available on request.
Metallurgical structure
Cut wire shot is obtained from drawn carbon steel wire, a cold-forming process that orients the metallurgical grain longitudinally and eliminates the internal porosity characteristic of cast products. The wire is cut into cylinders (AS-CUT format, designated CW) and subjected to a quench-and-temper heat treatment to reach the specified hardness, producing a fine, homogeneous tempered martensitic structure distributed throughout each grain. As a result, each particle has uniform density, with no microvoids or casting inclusions, ensuring constant energy delivery on each impact and a media life several times longer than equivalent cast shot. On this base grain, an optional mechanical conditioning process (rotation between particles and/or impact against a controlled surface) progressively rounds the edges to obtain the CCW (conditioned), DCCW (double conditioned) and SCCW (spherically conditioned) grades, selectable according to the geometry of the component to be treated and the process specification.
Granulometry — CW 17 to CW 47 grades
Cut wire shot is classified by the nominal diameter of the wire from which it is obtained, in a nomenclature proper to the line with the CW (cut wire) prefix followed by a number indicating the diameter in thousandths of an inch. The standard line covers eight grades from CW 17 (0.4 mm) to CW 47 (1.2 mm), with direct equivalence to spherical shot SAE J-444 of the same nominal size. CYM Materiales supplies the full range and, given the nature of the cutting process, allows special granulometries outside the standard line on request:
| CW grade | Nominal diameter (mm) | SAE J-444 equivalent (shot) |
|---|---|---|
| CW 17 | 0.40 | S-170 |
| CW 20 | 0.50 | S-200 |
| CW 23 | 0.60 | S-230 |
| CW 28 | 0.70 | S-280 |
| CW 32 | 0.80 | S-330 |
| CW 35 | 0.90 | S-360 |
| CW 41 | 1.00 | S-390 |
| CW 47 | 1.20 | S-460 |
Classification per the manufacturer cut wire nomenclature. The grade number (17, 20, 23, etc.) corresponds to the original wire diameter expressed in thousandths of an inch: CW 17 = 0.017", CW 47 = 0.047". Unlike cast spherical shot —where the SAE grade defines a passing sieve— in cut wire the grade directly defines the grain diameter, providing a noticeably narrower and more uniform dimensional distribution. Special granulometries outside the standard line (CW 12, CW 14, CW 54, CW 62 and others) are available on request for specific contractual processes. For the full dimensional tolerance matrix by grade and standard, download the technical datasheet in PDF.
Hardness
Cut wire shot hardness is fixed from supply and obtained through quench-and-temper heat treatment of the drawn wire, with no need for work hardening during operation. CYM Materiales supplies the CW line in four standard hardness levels between 56 and 65 HRC, covering from medium Almen intensity shot peening on mechanical components to certified aerospace processes with specific contractual microhardness requirements. The choice of level depends on the applicable standard, the target Almen intensity and the substrate hardness:
| Level | Vickers (HV 0,5/1) | Rockwell C (HRC) | Typical application |
|---|---|---|---|
| Standard | 610 – 670 | 56 – 59 | Industrial shot peening — gears, transmissions |
| Medium | 640 – 700 | 57 – 60 | Medium-demand shot peening — springs, leaf springs |
| High | 670 – 730 | 59 – 61 | High-intensity shot peening — critical fatigue parts |
| Extra high | 750 – 850 | 62 – 65 | Certified aerospace shot peening AMS and BAC-Spec |
Measurements taken with Vickers method (HV) under loads of 0.5 to 1 kgf, in line with industrial practice for cylindrical and conditioned grains. Conversion to Rockwell C (HRC) follows standard ASTM E140 tables. Other hardness levels outside the standard ranges are available on request, including specific levels required by proprietary aerospace standards (GE-Spec, BAC-Spec) or AMS 2431 certified processes. Unlike cast spherical shot —where hardness can vary between particles due to casting heterogeneity— in cut wire the hardness is notably more uniform within the lot due to the metallurgical homogeneity of the drawn wire, a key feature for Almen intensity repeatability in certified processes.
SHOT SELECTION BY APPLICATION
Which application do you need to perform?
Select the application to see the recommended CW grade, hardness and rounding grade.
The table shows the most commonly used CW grade, hardness and rounding for each application, according to industrial practice. It is not a prescriptive rule: most applications accept more than one valid combination, and certified aerospace processes may require specific combinations according to the applicable standard (AMS 2431, AMS-S-13165, GE-Spec, BAC-Spec). The final selection depends on the target Almen intensity, the available equipment and the contractual specifications. Consult our technical team for a specific recommendation.
| Application | CW 17–CW 23 | CW 28–CW 32 | CW 35–CW 47 | Standard / Medium | High / Extra high | CW (as-cut) | CCW / DCCW / SCCW |
|---|---|---|---|---|---|---|---|
| Industrial shot peening of gears and transmissions | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Shot peening of helical springs | ✓ | ✓ | ✓ | ✓ | |||
| Stress peening of leaf springs under tension | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Shot peening of bearing seats | ✓ | ✓ | ✓ | ✓ | |||
| Localised shot peening on stress concentration areas | ✓ | ✓ | ✓ | ||||
| Aerospace shot peening — turbine blades | ✓ | ✓ | ✓ | ||||
| Aerospace shot peening — landing gears | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Certified aerospace shot peening per AMS 2431 | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| Centrifugal wheel shot peening (SAT family) | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Air blasting shot peening (nozzles + CNC) | ✓ | ✓ | ✓ | ✓ |
RESOURCES AND RELATED LINKS
Technical data sheet, alternative abrasives and technical reports
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