High-Performance Sealing Hardware
APM Hexseal Page
Sealing Solutions ebook
High-Performance Sealing Hardware

Sealing hardware fastens disparate components together to prevent process fluids from escaping and external contaminants from entering. Proper seals ensure mechanical and electrical equipment continue to perform efficiently and effectively.

Overview

Seelskrews® and Seelbolts® self-sealing fasteners create a reliable and reusable seal that prevents process fluids from escaping and contaminants from entering even in high impact, high pressure and highly demanding environments.

Seelnuts® self-sealing hardware products are one of APM Hexseal's earliest innovations. They offer reliable performance in temperatures ranging from 103° to 400° F. They are compatible with standard screws, bolts, and studs, making them quick and easy to install in a variety of applications.

Seeloc® washers consist of molded silicone rubber material bonded to stainless steel washers. They accommodate temperatures ranging from 103° to 400° F and internal and external pressures up to 100 psi. They can be used with any standard screws, bolts, and studs in sealing applications. A heavy-duty variation is offered that provides at least 50% greater torque handling capacities.

Video

Seelskrews® and Seelbolts®

Fasteners often require additional sealing additives, such as messy liquid or paste compounds, to prevent leaks and ensure reliable, secure holds. APM Hexseal’s patented Seelskrews® and Seelbolts® combine dependable fastening hardware with built in weatherproof sealing materials. As a result, our self-sealing screws and bolts offer a reliable and reusable seal, without messy goops that are difficult and tedious to apply. Our sealing fasteners are critical in preventing or containing contamination from dust, air, water, lubricants and other liquid or gaseous substances.

They are also vibration-resistant, making them a great choice for applications that encounter day-to-day jarring, or repetitive movement. Should you need a more serious level of vibration-resistance, our screws and bolts are available with additional locking features, such as self-locking pellets, strips, and patches.

APM Hexseal Seelskrews and Seelbolts

APM Hexseal’s Seelskrews® and Seelbolts® offer a variety of unique features not shared by traditional fastening and sealing hardware, including: 

  • Positive seals while under pressure or vacuum conditions
  • Easy installation
  • Removable and reusable
  • Compatibility with all surface finishes
  • Broad operating temperature range from -160°F to 500°F (-106°C to 260°C)
  • Full 360° metal-to-metal contact for fastening integrity
  • Uniform high-strength designs
  • UL- and CSA-recognized

Seelskrews® and Seelbolts® are available in many standard thread sizes and with various O-ring elastomer options. Some additional customizations include specialty thread-forming variations, tamper-resistant drives, thread captivation, and paint and finish options.

  • Screw/Bolt Material: 18/8 Stainless Steel, passivated
  • Threads: Imperial— Class 2A; Metric— Class 6g
  • O-Ring Elastomer: Silicone conforms to A-A-59588, Class 2, GR60 or GR70, Red
  • Temperature Range: -80° F to +425° F ( -62° C to +219° C)
  • Pressure Range: Up to 20,000 psig internal and external (subject to clearance hole dimensions).
  • Resistant to: Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.

APM Hexseal Seelskrews and Seelbolts

Metric Pan Head with Cross Recess Drive (Phillips)

APM Hexseal Seelskrews and Seelbolts

Imperial Pan Head with Cross Recess Drive (Phillips)

APM Hexseal Seelskrews and Seelbolts

APM Hexseal Seelskrews and Seelbolts

Metric Pan Head with Slotted Drive

APM Hexseal Seelskrews and Seelbolts

Imperial Pan Head with Slotted Drive

APM Hexseal Seelskrews and Seelbolts

APM Hexseal Seelskrews and Seelbolts

Metric Hex Head Bolt

APM Hexseal Seelskrews and Seelbolts

Imperial Hex Head Bolt

APM Hexseal Seelskrews and Seelbolts


APM Hexseal Seelskrews and Seelbolts

Imperial Flat Head with Cross Recess Drive (Phillips)

APM Hexseal Seelskrews and Seelbolts

Videos

Seelnuts®

Seelnuts® are available in standard thread sizes as well as a variety of different elastomers to suit your application needs. Seelnuts® can also be supplied with self-locking pellets for applications where excessive vibration is an issue.

APM Hexseal Seelnut

APM Hexseal’s Seelnuts® are also reusable, meaning that they can be easily removed and reapplied, re-establishing the same reliable seal when torqued.

  • Nut Material: Low Carbon Steel with Zinc-Chromate Plating
  • Threads: Imperial— Class 2B; Metric— Class 6H
  • Elastomer: Silicone conforms to A-A-59588, Class 3A, GR60, Red
  • Temperature Range: -103° F to +400° F ( -75° C to +204° C)
  • Pressure Range: Up to 20,000 psig internal and external (subject to clearance hole dimensions).
  • Resistant to: Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
  • Shelf Life: Excess of 25 years.

APM Hexseal Seelnut

Metric Seelnuts® - Standard Nut Style

APM Hexseal Seelnut

Imperial Seelnuts® - Standard Nut Style

APM Hexseal Seelnut

Imperial Seelnuts® - Jam Nut Style

APM Hexseal Seelnut

Torque Values for Seelskrews®, Seelbolts® & Seelnuts®

The suggested torque values shown here were calculated using 18-8 Stainless Steel parts and are based on a dry, non-lubricated thread surface. Lubricated fasteners require less torque than shown on this table.

APM Hexseal SeelNut SeelSkrew SeelBolt Torque

Seeloc® Washers

State-of-the-art Seeloc® washers consist of strong, corrosion-resistant stainless steel bonded to flexible silicone rubber, for a soft yet durable sealing and fastening solution.

Seeloc® Washers work in combination with traditional bolts, screws, or studs to create an airtight seal around the fastener. The silicone contact surface features a continuous ridge that creates a 360° sealing barrier around the periphery of the washer face when compressed. The silicone rubber also forms a seal under the head of the associated fastener and makes full vertical contact with the threads/shank, making for a complete, high-pressure seal unlike any other.

APM Hexseal Seeloc Washers

  • UL Recognized
  • IP66/68 rated
  • Air & liquid-tight
  • Greater than 25-year shelf-life

Metric Seeloc® Washers

Standard Seeloc metric washers are made from 18/8 stainless steel and feature a broad temperature range of -103°F (-75°C) to 400°F (204°C), internal and external pressure tolerances up to 100 psig, and a shelf life over 25 years. They also resist dust, fungus, most acids and oils, splash, salt spray, sunlight, and ozone.

APM Hexseal Seeloc Washers

APM Hexseal Seeloc Washers

 

Imperial & Heavy Duty Seeloc® Washers

 APM Hexseal also offers Heavy Duty Seeloc® Washers, capable of handling torque values at least 50% higher than original Seeloc® Washers. Currently available in both 1/2” (14mm) and 1” (25.4mm) O.D. sizes, these sealing washers are perfect for a myriad of sealing requirements, from medical equipment and chemical handling to construction equipment and food processing.

APM Hexseal Seeloc Washers

APM Hexseal Seeloc Washers

Bonded Sealing Washer Materials

Seeloc Washers are manufactured using stainless steel and molded using a variety of elastomers. Though silicone is the standard elastomer material for Seeloc® Washers, additional elastomer material options include EPDM, neoprene, and fluorosilicone.

  • Silicone offers superior heat resistance as one of its primary properties. High-temperature variations can withstand intermittent temperatures up to 500°F or continuous temperatures up to 437°F.
  • EPDM is a lower-cost material that offers excellent ozone, weather, and heat resistance. Sealing washers made from EPDM work well for outdoor applications.
  • Neoprene is a versatile facing material with resistances to chemicals, sunlight, ozone, weathering, and aging. Neoprene sealing washers perform well in a wide range of joint sealing applications.
  • Fluorosilicone combines the benefits of silicone and fluorocarbons, offering superior low temperature performance and high resistances to heat, flame, chemicals, weather, water, ozone, and more.

Bonded sealing washers provide superior performance over conventional sealing/fastening solutions in many ways. Some of the benefits offered by bonded sealing washers include: 

Better leak prevention

Bonded sealing washers eliminate the risk of premature loosening in response to vibration or noise, resulting in enhanced leak prevention.

Versatility

Various bonded sealing washer designs offer superior durability in extreme-temperature, high-torque, and otherwise demanding environments. Our Seeloc Washers are available in both imperial and metric measurements.

Toughness

The strong elastomers used in bonded sealing washers resist tearing or shearing forces during tightening. Our Heavy Duty Seeloc Washers can handle at least 50% more torque than standard Seeloc Washers.

Applications of Bonded Sealing Washers

Bonded sealing washers see broad use in a wide range of industries, including aerospace, agriculture, automotive, construction, marine, military, and mining.  In addition to conventional mounting holes, Seeloc® Washers work with oversized holes and adjustment slots with non-standard shapes. They also work well for sealing knockout holes in electrical boxes and cabinets. The durability of Seeloc® Washers ensures they can be removed and reused, making them well-suited to applications that require periodic maintenance or adjustments.

Equipment and systems that most commonly use bonded sealing washers include:

  • NEMA rated boxes and electrical enclosures
  • Hydraulics and braking systems
  • HVAC products
  • Industrial and construction equipment
  • Marine electronics

 

Quality

UL Recognized (UL Type 4X/6 enclosures) and IP66/68 rated, Seeloc® Washers provide a high-performance, air- and liquid-tight seal that is ideal for applications where spray, vapors or wash-downs are present, or where there is a concern of damage from a wide range of contaminants, such as dust, oils and salt build-up.

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Torque Values for Seeloc® Washers

APM Hexseal Seeloc Washers

The maximum torque values listed are for clean, dry parts free of lubricants and thread lockers. All washers were tested using a standard pan head screw or hex bolt through a Stainless-Steel plate with #4 brushed finish with maximum hole size as listed.

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