Como accesorio crucial de conexión de cables y equipos, el prensaestopas desempeña un papel fundamental en la protección de los cables, la prevención de la entrada de agua y polvo y la puesta a tierra. Ya sea en la automatización industrial, el control eléctrico, la marina, la minería u otros entornos exigentes, elegir el prensaestopas adecuado es esencial. Analicemos hoy los principales tipos de prensaestopas, sus características y cómo elegir el que mejor se adapte a sus necesidades.

¿Qué es un prensaestopas?

En pocas palabras, un prensaestopas es un accesorio que se instala en el punto de entrada de cables del equipo. Sujeta el cable, evita que se salga accidentalmente y lo impermeabiliza contra el agua y el polvo. También ofrece conexión a tierra y apantallamiento, garantizando conexiones eléctricas seguras y estables.

Entre las funciones clave se incluyen:

• Sujeción de cables y prevención de tirones o roturas accidentales
• Mantener el polvo y la humedad fuera del equipo
• Conexión eléctrica a tierra y apantallamiento para reducir las interferencias electromagnéticas
• Proteger las cubiertas de los cables y alargar su vida útil

Los prensaestopas se utilizan ampliamente en maquinaria, automatización industrial, marina, tránsito ferroviario, minería y muchos otros campos. Son indispensables en cualquier sistema eléctrico.

Principales tipos de prensaestopas

Cable glands come in many varieties. They can be classified by structure, material, protection level and thread standard. Here’s a detailed overview of each dimension, with the specifications and indicative FOB prices that decide most B2B orders:

1. Por estructura

The five structural families below are compared on the three factors that decide most B2B orders: specification, application and price.

Price basis: indicative FOB Ningbo / Shanghai unit prices for nickel-plated brass, 1,000 pcs per size, standard export packing. Stainless steel, Ex-certified, custom-thread and private-label versions are quoted separately — see the sourcing section below.

Prensaestopas estándar

Body material nylon PA66 (UV-stabilised) or nickel-plated brass; threads PG7–PG48, M12–M63 or NPT; cable OD 3–44 mm; IP68, with IP66 available on request. The general-purpose choice for non-armoured plastic or rubber-sheathed cable, and the highest-volume item in most OEM programmes.

Application: control cabinets, junction boxes, indoor panels, light-duty outdoor equipment.
Indicative price: US$0.08–1.20 per pc, FOB, 1,000 pcs per size.

Prensaestopas de alta resistencia

The same sealing principle as a standard gland, but with a thicker body wall, a longer thread and a larger sealing nut; threads PG9–PG63 or M16–M63; cable OD 6–52 mm; nickel-plated brass or stainless steel 304/316; IP66–IP68. Specified wherever vibration, washdown or mechanical impact would fatigue a light-duty gland.

Application: machinery, food and beverage washdown, high-vibration equipment, outdoor enclosures.
Indicative price: US$0.60–4.80 per pc, FOB, 1,000 pcs per size.

Prensaestopas antideflagrante

Flameproof or increased-safety construction with a controlled flame path and a certified sealing arrangement; M20×1.5, M25, PG13.5–PG29; cable OD 6–32 mm; brass or stainless steel 316; IP66/IP68; supplied with ATEX / IECEx Ex e or Ex d certification. On site it is the certificate, not the thread size, that the inspector asks to see.

Application: Zone 1 and Zone 2, oil and gas, chemical plants, refineries, mining.
Indicative price: US$2.50–14.00 per pc, FOB, 300 pcs per size.

Prensaestopas EMC

Nickel-plated brass body with a 360° contact spring or grounding insert that bonds the cable screen to the enclosure; M12–M63 or PG7–PG48; cable OD 3–38 mm; IP68. Low transfer impedance is the whole point: the screen has to be terminated at both ends, or the gland is only doing half its job.

Application: VFD motor cables, drives, instrumentation, data centre and telecom cabinets.
Indicative price: US$0.90–6.50 per pc, FOB, 1,000 pcs per size.

Armoured Cable Gland (SWA / STA)

Includes an armour clamping ring and an earth tag so the steel wire or tape armour is mechanically anchored and electrically bonded; M20–M63 or PG13.5–PG48; cable OD 10–52 mm; brass or stainless steel; IP66/IP68. These are sized on the armour wire count and diameter, not on the cable OD alone — send the cable datasheet when you request a quotation.

Application: buried and tray-run armoured feeders, process plants, rail, mining, petrochemical.
Indicative price: US$1.20–7.50 per pc, FOB, 1,000 pcs per size.

Single vs Double Compression — and Other Structural Options

Alongside the five families above, gland bodies are also described by how many sealing stages they use and what the cable entry is made of. The distinction matters when you write the specification, because a single-compression gland is a different part from a double-compression gland at the same thread size, and the two are not interchangeable on the same cable.

• Single compression
  One compression ring grips and seals the cable in a single action. Simple, fast to install, and the right choice for indoor control panels, junction boxes and general machinery.
• Double compression
  Seals on both the inner and the outer layer of the cable, so the barrier holds even when the cable is flexed or pulled. Specified for factories, power plants and other high-sealing installations.
• Flexible hose / spiral entry
  The cable enters through a flexible hose instead of a rigid body, absorbing vibration and mechanical stress in high-temperature or moving machinery.
• PVC
  An economical body for instrument and control cables in light-duty indoor environments where corrosion and UV exposure are not a factor.

2. Por material

• Prensaestopas metálico: Los materiales más comunes son el latón, el acero inoxidable y el aluminio. Ofrecen resistencia a la corrosión y a las altas temperaturas, por lo que son ideales para uso industrial y al aire libre.
• Prensaestopas de plástico: Suelen ser de nailon, ligeros y económicos, adecuados para cables ligeros y aplicaciones de interior.
• Materiales especiales: Por ejemplo PVDF, que ofrece una resistencia superior a la corrosión en entornos químicos.

The specification differences matter more than the label, so here is the same comparison across materials:

3. En Nivel de protección IP

• Prensaestopas impermeable: Con sellado IP68, evita la entrada de agua.
• Prensaestopas antipolvo: Mantiene el polvo fuera, protegiendo los componentes internos.
• Prensaestopas resistente a la corrosión: Adecuado para entornos marinos o químicos altamente corrosivos.

For a quick comparison, the three protection-driven families break down as follows:

4. By Thread Standard

Thread compatibility decides whether the gland threads cleanly into your enclosure, and a mismatched thread is one of the most common reasons an order is rejected on arrival. Three standards cover almost every B2B requirement:

PG and metric threads are not interchangeable. PG13.5 is not an M20 substitute — the outside diameters differ and the sealing face sits in a different position, so a gland that appears to thread in will still not seal. Metric, PG and NPT sizes are all produced on the same line, so the thread standard is a specification choice rather than a sourcing constraint. Confirm it against your drawing, or against the gland you are replacing, before you order.

In practice the type rarely stands alone. The same plant usually needs a nylon standard gland on a control cabinet, a shielded gland on the VFD motor feeder and a stainless steel armoured gland on the incoming supply — three different types, three different purchase channels, one bill of materials. The application scenarios below show how the environment itself dictates the type.

Escenarios de aplicación del prensaestopas

La elección del prensaestopas depende del entorno de aplicación. He aquí algunos escenarios típicos:

• Automatización industrial: Requiere prensaestopas resistentes al polvo, al agua y duraderos para maquinaria y armarios de control.
• Tránsito marítimo y ferroviario: Necesita prensaestopas impermeables y resistentes a la corrosión para la seguridad eléctrica.
• Minería y entornos peligrosos: Los prensaestopas antideflagrantes son esenciales para la seguridad.
• Comunicación y centros de datos: Los prensaestopas EMC reducen las interferencias electromagnéticas y garantizan la estabilidad de las señales.

Cómo elegir el prensaestopas adecuado

Elegir el prensaestopas adecuado garantiza que su sistema eléctrico sea más seguro y fiable. Tenga en cuenta estos factores clave:

1. Cable diameter and hole size
   Measure the cable’s outer diameter (OD), not the nominal wire size, and match it to the gland’s clamping range — a seal that is too loose lets water past, one that is too tight damages the sheath. Note whether the cable is armoured or non-armoured, because the two need different gland bodies.
2. Thread standard and size
   Confirm which thread your enclosure takes — metric, PG or NPT — and the exact size. This is the single most common cause of a rejected order, and it cannot be corrected on site.
3. Material selection
   Match the material to the environment and to lifecycle cost: nylon PA66 for economy and insulation, nickel-plated brass for industrial strength, and stainless steel 304/316 for washdown, marine and chemical duty.
4. Protection level
   Set the IP target from the real exposure — IP66 for outdoor weather, IP68 where immersion or washdown is possible — and add corrosion-resistant, explosion-proof or EMC construction if the site demands it.
5. Special functions
   Specify shielding for VFD and instrumentation cables, high-temperature construction for ovens and engine bays, or a chemically resistant body for chlorine and acid duty.
6. International standards and certifications
   Check the product against EN 50262, IEC 60529 and IEC 60079 where they apply, and confirm the paperwork your market requires: CE, RoHS, REACH, and ATEX / IECEx for hazardous areas.

Factory-Tested IP Data

A datasheet rating is only useful if it can be reproduced in production. Our in-house test bench verifies ingress protection on production samples in line with IEC 60529 and ISO 20653. The results below are sample-based and depend on the cable OD matching the gland’s clamping range and on correct tightening torque.

This is why the cable OD range matters as much as the IP number: an M20 gland rated IP68 still lets water in if the cable measures 8 mm while the gland’s clamping range starts at 10 mm. Send your actual cable OD and we will test and match the exact model rather than the nearest catalogue size.

Sourcing Cable Glands: OEM Inquiries, MOQ and Certifications

Once the type is settled, the buying decision comes down to tooling and branding, minimum order quantity, and paperwork.

OEM inquiries. For private-label orders we need four inputs before quoting: the gland type and thread standard (PG, metric or NPT), the cable OD range, the body marking you want laser-etched (brand, size, IP code), and the packing format — bulk bag, poly-bagged with your label, or retail blister. Custom bodies, non-standard thread lengths and colour-matched nylon (black, grey, white or a specific RAL) are tooled in-house: a new nylon mould takes 25–30 days, while laser marking on an existing mould starts with the first production run.

MOQ. Standard nickel-plated brass and nylon glands ship from 1,000 pcs per size with no tooling charge; trial orders of 100–500 pcs are available on stock sizes so you can validate the fit before committing to volume. Stainless steel and Ex-certified glands carry a 300 pcs per size MOQ because they are machined to order. Mixed containers are welcome — we build the size mix across types so one 20 ft container is filled at a single freight cost.

Certifications. Our glands are produced under ISO 9001, and the documents most buyers need ship with the first order: IP68 immersion test report, CE declaration, RoHS and REACH statements, and material certificates for brass and stainless steel. Explosion-proof models come with ATEX / IECEx certificates, and third-party inspection (SGS, TÜV, BV) can be arranged at cost. If your market needs a specific standard — EN 50262, EN 62444, UL 514B or a local approval — raise it at the inquiry stage: it changes the body design, not just the paperwork.

Send us the type, the thread and the annual volume and we will return a specification drawing, a certificate pack and an FOB quotation within one working day — contact us here.

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