SECO7 Seal FAQs

SECO7 seals are all-metal crush gaskets for 37° flared tube fittings. When torqued, the seal deforms and work-hardens, creating a permanent barrier against leaks.

Unlike elastomeric O-rings, SECO7 seals will not degrade, extrude, or fail under heat, vibration, or chemical exposure.

Aerospace, defense, marine, motorsports, oil & gas, and high-performance hydraulic and pneumatic systems.

SECO7 seals are available in four materials.

• Aluminum (Code A): 1100-O per AMS 4001 or QQ-A-1876.
• Copper (Code C): C10100/C10200/C11000 per ASTM B152.
• Nickel (Code N): N02201 per ASTM B162 / AMS 5553.
• Stainless Steel (Code S): 305/316 per ASTM A240.

Following are the recommendations for chosing the

• Aluminum (A): Use on all aluminum fittings.
• Copper (C): Best for non-corrosive fluids and gases.
• Nickel (N): Preferred for hydrocarbon fuels and oils.
• Stainless Steel (S): Recommended for corrosive environments and spaceflight.

From 1/8″ through 3″ line sizes, per AS4824.

❌ No. SECO7 seals are designed for one-time use only. Replace whenever fittings are disassembled.

When installed correctly, SECO7 seals last the life of the fitting, with zero recorded field failures.

All-metal construction allows sealing from cryogenic lows to high aerospace service temperatures (material dependent).

Leak-free performance proven up to 20,000 PSI, depending on size and material.

The conical crush design maintains seal integrity under shock and vibration.

Yes. SECO7 seals meet AS4824 and are used in spacecraft, satellites, and defense aircraft.

Stainless steel seals are recommended for saltwater and marine environments.

SECO SEALS is ISO9001 and AS9100 certified. SECO7 seals conform to AS4824 Aerospace Standard.

SECO7 seals have a proven record of 100% reliability, with zero documented field failures.

The following steps are the proper installation procedure.

• Insert seal between the 37° flare and fitting nose.
• Hand-thread the nut until snug.
• Torque to published values (Tables AI, AII, AIII).
• Wait 10–15 seconds for the seal to yield.
• Re-torque to the same value.

Yes — use precision calibrated torque wrenches for accurate installation.

Yes — SECO7 seals fit SAE J514 fittings.
➡️ However, fitting ends per AS4395 are preferred for aerospace and other critical applications.

Always use the values in SECO7 published torque tables or fitting manufacturers recommendations.

The flare and fitting nose should seat flush, with no visible gaps.

The following installation errors must be avoided.

• Over-torquing beyond SECO7 specs
• Cross-threading or forcing assembly
• ❌ Reusing seals — SECO7 seals are one-time use only

Yes. Use nickel seals for hydrocarbon-based hydraulic fluids, or stainless steel seals for corrosive fluids.

Yes. Copper seals are ideal for dry, non-corrosive gases, while stainless steel seals are used in corrosive pneumatic systems.

Recommendations are:

• Nickel seals are best for hydrocarbons (aviation fuel, diesel, kerosene, lubricants).
• Stainless steel seals are recommended for corrosive fluids and chemicals.
• Copper seals may be used in non-corrosive gas service.

Yes. Nickel and stainless steel seals are widely specified in U.S. defense aerospace programs.

All-metal tube fitting assembly construction ensures reliability under vacuum, temperature extremes, and vibration.

Yes. Available options include:

• Tin (T): per MIL-T-10727 / AMS 2408-2.
• Silver (S): per AMS 2410 “K” flash plate.
• Gold (G): .00050″ thick per MIL-G-45204, Type III, Class 5, Grade A.

Improves anti-galling properties, aids installation, and provides moderate corrosion resistance.

Reduces friction, enhances conductivity, and provides excellent galling resistance.

Gold plating provides maximum corrosion resistance and inertness, ideal for aerospace and satellite applications.

XYLAN 1424 is a fluoropolymer coating that enhances lubricity, wear resistance, and corrosion protection. SECO7 seals with XYLAN 1424 are in development for marine and aerospace environments.

Yes. SECO SEALS can provide coatings to OEM or military specification.

Not by default. Standard parts are not oxygen-cleaned. Options include:

• L code: cleaned per MIL 1330 Rev. D.
• SP code: specialty cleaned per customer specification.

SECO7 seals are available in the following quantities.

• Tubes of 50 (Dash 2–6)
• Tubes of 25 (Dash 7–24)
• Tubes of 10 (Dash 28–48)
• X code: individually packaged in plastic boxes
• V code: tubes of 15 (Dash 2–16)