SAEBRASS
Solid Brass Fitting

Machined solid brass SAE adapter — converts between service port and hose thread sizes so the connection you have meets the fitting you need

R-410ARATED
High-Pressure Compatible

Rated for R-410A and high-pressure HFC / A2L systems — brass body and SAE threads hold under full service pressure without weeping

LEAKFREE
Precision SAE Threads

Precision-cut SAE flare threads seat clean and leak-free — no thread tape, no weeping, no lost refrigerant at the connection

HCPRODESIGNED
Built to Black Knight Spec

HCPRO-designed to Black Knight specifications and quality-control standards — engineered in Miami, built to spec by our manufacturing partner

Why Black Knight

Solid brass.

Leak-free SAE.

R-410A rated.

HCPRO Black Knight SAE brass adapters convert between service-port and hose thread sizes so your connection always meets your fitting — precision SAE threads, R-410A and A2L high-pressure rated. See the hero pills for this adapter's exact size conversion.

Solid brass, precision SAE threads

Machined from solid brass with precision-cut SAE flare threads that seat clean and seal leak-free — no thread tape, no weeping at the connection. The adapter that makes your 1/4″ hose meet a 5/16″ R-410A port, or your 5/16″ hose meet a 1/4″ gauge, without losing refrigerant at the junction. See the hero pills for this adapter's exact size conversion.

R-410A and A2L high-pressure rated

Brass construction and SAE threads hold under R-410A and modern A2L high-pressure service conditions. Whether you're adapting a mini-split's 5/16″ low-side port or connecting legacy 1/4″ gauges to a newer system, the fitting holds pressure without weeping or blowing the flare.

The fitting that saves the service call

Nothing stops a service call faster than the wrong fitting size. A few brass adapters in the bag means your hose always meets the port — 45° swivel for tight engine bays and condenser compartments, straight for open connections. Cheap insurance against a 30-minute parts-store run.

Full Product Description

The HCPRO HCAD140 is a reverse adapter that lets you run a 5/16" R-410A charging hose into a standard 1/4" SAE service port.

Key features

  • 5/16" SAE hose × 1/4" SAE port — the reverse of a standard R-410A adapter
  • Use your 5/16" R-410A hoses on legacy 1/4" equipment
  • Solid brass, high-pressure rated, leak-tight
  • Compact inline body for clean manifold connections

Bridges 5/16" R-410A tooling to 1/4" service ports without a second hose set.

Technical specifications

Brass adapter specs that seal leak-free.

HCPRO Black Knight SAE brass adapter — solid machined brass, precision SAE flare threads, R-410A / A2L high-pressure rated. Converts between service-port and hose thread sizes. See hero pills for this model's exact conversion. HCPRO-designed to Black Knight specifications.

Type
SAE thread/size adapterConverts between service-port and hose thread sizes — see hero pills for this model
Material
Solid machined brassCorrosion-resistant, holds pressure without weeping
Size conversion
See hero pills / product titleHCAD45S: 1/4″M × 5/16″F 45° swivel · HCAD410: 1/4″M → 5/16″F · HCAD140: 5/16″ hose × 1/4″ port
Thread standard
SAE flareStandard HVAC service threads — fits manifolds, hoses, and service ports
Pressure rating
R-410A / A2L high-pressureHolds under full HFC and A2L service pressure
Configuration
45° swivel or straight (per model)45° swivel for tight access; straight for open connections
Compatible refrigerants
R-410A, R-22, R-134a, R-404A, R-32, R-454BAll common HFC and A2L refrigerants
Seal
SAE flare — no tape requiredMetal-to-metal flare seal, leak-free when seated
Application
Port/hose size conversionConnect mismatched hose and service-port sizes without losing refrigerant
Brand
HCPRO Black KnightThe HCPRO professional HVAC service tool line
Reusable
Yes — permanent service-bag toolBrass holds up to repeated connect/disconnect cycles
Country of origin
ChinaHCPRO-designed in Miami to Black Knight specifications, built to spec and quality-controlled to OEM standards
Best paired with
Manifolds, charging hoses, gaugesBridges any SAE size mismatch in your service kit
Warranty
1-year limitedCovers manufacturing defects under normal professional use
In the box

The brass adapter, ready to bridge any SAE mismatch.

HCAD140 Adapter 5/16" SAE Hose x 1/4" SAE Port – Brass Fitting
HCPRO Black Knight SAE brass adapterSolid brass, precision SAE threads — see hero pills for this model's size conversion
Pre-installed flare sealsMetal-to-metal SAE flare — leak-free when seated, no thread tape needed
Configuration45° swivel or straight per model — see product title
Black Knight fitting referenceSize conversion guide, refrigerant compatibility, torque reference
Customer reviews

What working techs say after putting it on the truck.

12,000+ HVAC pros served
4.9★ Average rating
94% Repeat buyers

Replace this with a real customer quote — what size mismatch it solved, how it sealed leak-free, saved a parts-store run.

Marcus T.HVAC TECH · MIAMI, FL
On HCPRO Black Knight SAE Brass Adapter

Replace this with a real customer quote — what size mismatch it solved, how it sealed leak-free, saved a parts-store run.

Jorge R.REFRIGERATION CONTRACTOR · ATLANTA, GA
On HCPRO Black Knight SAE Brass Adapter

Replace this with a real customer quote — what size mismatch it solved, how it sealed leak-free, saved a parts-store run.

Derrick W.COMMERCIAL HVAC · PHOENIX, AZ
On HCPRO Black Knight SAE Brass Adapter
Used it on a job?

Share your shop notes

Write a review

Tools that pair with the HCAD140.

Common questions

Answers from the warehouse floor.

Still stuck? Call our techs at 305-720-0044.

Does HCPRO warranty the products?

Yes — every HCPRO Black Knight product ships with a 1-year limited warranty against manufacturing defects under normal professional use. We'll replace the manifold, gauges, or hoses if they fail to meet stated specs. See our full warranty terms.

Which adapter do I need?

Match your hose size to your port size. HCAD45S (1/4″ male × 5/16″ female, 45° swivel) connects a 1/4″ hose to a 5/16″ R-410A port in tight spaces. HCAD410 (1/4″ male → 5/16″ female) is the straight version. HCAD140 (5/16″ hose × 1/4″ port) goes the other direction. Check the title and hero pills for the exact conversion.

Why do I need a 5/16″ adapter for R-410A?

Many R-410A systems use a 5/16″ SAE low-side service port (vs the older 1/4″ standard) to prevent accidental cross-charging with lower-pressure refrigerants. If your hoses are 1/4″, you need a 1/4″-to-5/16″ adapter (HCAD45S or HCAD410) to connect. The 45° swivel version helps in tight condenser and mini-split compartments.

Will it leak at the connection?

No — these use precision SAE flare threads that seal metal-to-metal when properly seated. No thread tape, no sealant needed. Hand-tighten plus a quarter turn with a wrench for a leak-free connection that holds R-410A and A2L high-side pressure.

What refrigerants is it rated for?

All common HFC and A2L refrigerants — R-410A, R-22, R-134a, R-404A, R-32, R-454B. Brass and SAE threads handle the full high-pressure service range.

45° swivel vs straight — which?

The 45° swivel (HCAD45S) angles the hose away from the port and rotates freely — essential in tight engine bays, packed condenser cabinets, and mini-split compartments where a straight connection would kink the hose or won't physically fit. The straight (HCAD410) is for open, accessible ports. When in doubt, the swivel works everywhere.

Do I need more than one?

Most techs keep a small set — a 45° swivel and a couple straight adapters cover nearly every size mismatch you'll hit. A few brass adapters in the bag is cheap insurance against a stopped service call and a parts-store run.

Can I return an unused adapter?

Yes — free returns within 30 days for unused adapters in original packaging. Read our full return policy.

Do you offer bulk pricing?

Yes — trade pricing here, volume discounts for shops stocking adapters across trucks. Email hcproproductsusa@gmail.com for a custom quote within 24 hours.