Cylinder Straight Bulkhead Hydraulic Adapter 1C-Y/1D-Y (Metric Tube to Metric Tube Through a Panel)

Why This Cylinder Straight Bulkhead Hydraulic Adapter 1C-Y/1D-Y Passes the Compliance Gate

The cylinder straight bulkhead hydraulic adapter 1C-Y/1D-Y is a long, straight steel adapter that carries a metric tube connection at each end and passes through a cylinder end wall, a panel or a frame member on the way. Its purpose is simple and specific: keep the hydraulic line continuous and sealed where it crosses a wall, instead of leaving a hole, a grommet and a chafing tube.

• Tube ends: two metric male threads, M12X1.5 to M52X2, matched row by row to a tube outside diameter.
• Through-wall section: a defined mounting diameter d with two hexes, S2 and S3, for clamping the adapter to the wall.
• Pressure groups from the drawing: 31.5 MPa and 16 MPa (light series L), 63 MPa, 40 MPa and 31.5 MPa (heavy series S).

Core Advantages

1. A sealed wall crossing, not just a pass-through hole: the cylinder straight bulkhead hydraulic adapter 1C-Y/1D-Y is clamped through the wall and sealed on the tube connections, so the wall penetration does not become a leak or chafe point.
2. Same tube system on both ends: both ends are metric male threads in the DIN 2353 / ISO 8434-1 family, so one adapter replaces a stack of a bulkhead fitting plus a reducing nipple.
3. Documented mounting diameter: the drawing states d and both hexes S2 and S3 for every row, so the panel hole and the spanner clearance can be checked before the wall is machined.
4. Light and heavy series in one matrix: 20 catalogue rows cover light series L from 6 mm to 42 mm tube and heavy series S from 6 mm to 38 mm tube.
5. Alignment and rotation control: the adapter is held by its own hexes, so the tube nuts can be tightened from either side without disturbing the other end.
6. Batch traceability: mill test reports, dimensional inspection reports and pressure test records are available per production batch on request.

Technical Specifications

What Is a Cylinder Straight Bulkhead Hydraulic Adapter?

It is a one-piece machined steel adapter with a male metric tube thread at each end and a longer body between them. The body passes through a wall opening and is clamped at the wall, so the tube line stays sealed and supported where it crosses.

This is a through-wall adapter, not a weld fitting and not a stud end for a port. It must not be confused with a bulkhead union that joins two tube ends directly at the wall, and it is not a substitute for a hose or tube support clamp away from the wall.

Connection 1 and Connection 2: Metric Male Tube Threads (E and F)

Both ends carry the same metric thread size in every row of this matrix, so the adapter passes a single tube size through the wall rather than reducing it.

Dimensional Data

Full Dimension Table (Part Number Matrix)

All dimensions in millimetres. Every row is transcribed from the current 1C-Y/1D-Y drawing.

Reading the table: E and F are the two tube threads, D1 and D2 are the tube outside diameters they serve, l1 and L1 give the body length, and d with S2 and S3 define the through-wall fitting. The pressure group applies to the whole row.

Thread Size and Dash Chart

The mounting diameter d grows with the row, so check the wall opening and the spanner clearance before selecting the size.

Material and Heat Treatment

Working Pressure and Operating Envelope

Working pressure is set by the pressure group of the row selected, together with the tube system and both tube joints, and by the way the adapter is clamped at the wall.

The wall joint must also be sound: a bulkhead adapter that is loose in an oversized hole loads the tube rather than the wall. The finished assembly is only as strong as its weakest member. (1 MPa is approximately 145 psi.)

Temperature Range

How to Read the Part Number Matrix

The code reads: series prefix, tube thread size code, and the letter Y, which marks the cylinder bulkhead family. Prefix gives the series and the number block gives the metric tube thread of both ends.

• Prefix 1C = light series; prefix 1D = heavy series.
• Number block: metric tube thread nominal diameter (12 = M12X1.5, 26 = M26X1.5).
• Letter Y = straight cylinder bulkhead body, with the through-wall section and two hexes.
• Suffix RN = supplied as a complete set with cutting ring and nut for the tube ends.

Example 1: 1C-16Y = light series, M16X1.5 at both ends for 10 mm tube, overall length 87 mm, mounting diameter d 22 mm, hexes 19 mm, 31.5 MPa group.

Example 2: 1C-45Y = light series, M45X2 at both ends for 35 mm tube, overall length 114 mm, mounting diameter d 50 mm, hexes 50 mm, 16 MPa group. The long body suits a thick cylinder end wall.

Example 3: 1D-30Y = heavy series, M30X2 at both ends for 20 mm tube, overall length 114 mm, mounting diameter d 38 mm, hexes 36 mm, 40 MPa group.

Selection and Ordering

Ordering the cylinder straight bulkhead hydraulic adapter 1C-Y/1D-Y is a four-step check: measure the tube outside diameter, confirm the wall thickness and hole size against d and L1, choose light or heavy series, then compare the pressure group.

Selection Checklist and Decision Table

Cross Reference Service

Send a photo or a dimension sketch of the adapter being replaced, or the tube size and the wall thickness. We measure both threads, the mounting diameter d, the body length and the hexes, then map the part to a 1C-Y/1D-Y row free of charge. We do not copy or re-badge another manufacturer’s part number.

Packaging and Logistics

Installation and Fitment Guide

Step-by-Step Assembly

1. Check the part number, both tube sizes and the mounting diameter d against the wall opening before assembly starts.
2. Deburr the wall hole and confirm that the adapter shoulder seats flat against the wall face, with no paint, weld spatter or burr trapped under it.
3. Clamp the adapter through the wall using the two hexes, and torque the lock nut or mounting hardware to the value for that thread and wall material.
4. Fit the tube nut with its cutting ring or cone on one end and tighten to the tube system torque table, holding the adapter by its hex.
5. Repeat on the second end, keeping the adapter from rotating so the first joint is not disturbed.
6. Pressure test the line and check both tube joints and the wall crossing for weeping before the machine returns to service.

Torque and Sealing Notes

• Use the torque table for the exact thread size, material class and finish involved, taken from the applicable standard data sheet or the drawing supplied with the order.
• The seal is made at each tube joint by the cutting ring or cone of the tube system. The wall crossing itself is a mechanical clamp, not a seal, so it must seat flat.
• Never use the tube-end hex to hold the adapter while tightening the wall nut, or the tube joint already made on the other side can be disturbed.
• Support long tube runs either side of the wall so that vibration loads are not taken by the adapter body alone.
• If a tube joint weeps after correct torque, check tube squareness and ring condition before adding more torque.

Installation Warnings

• Do not fit this adapter into an oversized or elongated wall hole and rely on the lock nut to pull it straight.
• Do not interchange light series and heavy series parts, even where a thread appears to start.
• Do not substitute a weld fitting, a 74 degree cone end, a 60 degree seat end or an O-ring boss stud end for either tube end.
• Do not use the adapter as a structural member or as a support for other components.
• Do not clamp the adapter on the thread section; clamp only on the wall section between the hexes.
• Do not exceed the pressure group of the selected row.

Applications and Industries

Cylinder end penetration: the most common use is a tube line entering the end cap of a cylinder, where the adapter also acts as the wall fitting.

Frame and panel crossings: mobile equipment frames, machine guards and enclosures where a tube line has to pass a structural wall.

Cross-standard equipment integration: a machine built to metric tube practice where the wall penetration was previously solved with a bulkhead union plus a reducing nipple.

Repair and replacement: tube size and wall thickness are measurable on site, so an unmarked adapter can usually be mapped to a row from dimensions alone.

High-pressure test benches: heavy series rows at 63 MPa and 40 MPa suit rigs where a tube run must cross a panel without a leak path.

Industrial plant: presses, power units and machine tools where a tube line crosses a housing wall and must stay serviceable.

Industry tags: hydraulic adapter, bulkhead adapter, cylinder bulkhead fitting, metric tube, DIN 2353, ISO 8434-1, panel penetration, hydraulic fitting.

OEM Customization and Quality Traceability

We manufacture hydraulic adapters and hose assemblies and support OEM programs with private labelling and laser marking of your own part number on the hex or shank. Custom body lengths, special mounting diameters, alternative materials and lock nut combinations are quoted from your drawing or sample, usually within 24 hours.

Every production batch is traceable. Parts pass a 100 percent pressure test before packing, and mill test reports, dimensional inspection reports and pressure test records are available with the shipment on request. Third-party inspection such as BV or SGS can be arranged. Our manufacturing system is certified to ISO 9001:2015 and ISO 18752.

FAQ

Q: What is a cylinder straight bulkhead hydraulic adapter 1C-Y/1D-Y used for?

A: It carries a metric tube line through a cylinder end wall, panel or frame member. Both ends are metric male tube threads, and the through-wall section is clamped at the wall so the crossing is sealed and supported.

Q: How do I choose the size?

A: Match the tube outside diameter to D1 and D2, then check the wall opening against the mounting diameter d and the body length l1 and L1. Both ends of every row in this matrix serve the same tube size.

Q: Are the two ends different sizes?

A: No. In the rows listed on this drawing both ends carry the same metric thread and the same tube size. If you need a wall crossing that also reduces the line, a separate reducing adapter is required.

Q: What pressure can this adapter take?

A: The pressure group of the row governs the limit: 31.5 MPa and 16 MPa for light series L, 63 MPa, 40 MPa and 31.5 MPa for heavy series S. The tube joints and the wall clamping must be rated at or above that group.

Q: Do you supply the lock nuts?

A: Lock nuts matched to the row thread and hex can be quoted and shipped with the adapters. State the wall thickness and material when ordering so the nut length is correct for the application.

Q: Is the wall crossing itself sealed?

A: The through-wall section is a mechanical clamp rather than a seal. Sealing happens at the two tube joints, so the wall face must be flat, clean and square to the adapter axis.

Q: Can I use it in a thin sheet metal panel?

A: Not directly. A thin or flexible panel needs a reinforcing boss or a doubler plate so the clamping load does not distort the panel or loosen the joint.

Q: What are your lead times?

A: Standard rows typically ship as a 7-day batch, custom sampling is available in about 48 hours for new drawings, and urgent quantities can move by air freight.

Request a Quote

Send us the tube outside diameter, the wall thickness and hole diameter, the tube series (light L or heavy S), the wall material and the quantity. With those five details we confirm the correct row of the cylinder straight bulkhead hydraulic adapter 1C-Y/1D-Y matrix, check the mounting diameter and the pressure group, and return a quotation within 24 hours.

Browse the full Hydraulic Adapters range for the complete family, or contact us to request a quote, mill test reports, and samples.