BB straight couplings with metric thread 

Straight couplings with male thread on both sides metric

Metric straight coupling body - metric threaded straight coupling ( with metric thread ). The most popular type of couplings used in power hydraulics intended for connecting flexible hydraulic hoses and connecting hydraulic pipes. Straight coupling threaded on both sides with external metric thread with 24° cone. Used in hydraulics for connections in oil systems. Made of free-cutting steel, coated with an anti-corrosion O-zinc layer in white passivation. Available in light version (L – up to 16 MPa) and heavy version (S – up to 32 MPa). Couplings are also available in reducing versions. Metric straight couplings are primarily used to connect hydraulic hoses. 

Straight reducing couplings - with two threads of different size 

The following category also includes metric reducing couplings. What is a straight reducing coupling with two different metric threads ? A straight reducing coupling with two different metric threads is a hydraulic component that enables the connection of hoses, pipes, or components with different metric thread diameters. Its main task is to reduce the connection diameter, allowing for a smooth transition between system components with different thread dimensions. These couplings ensure the tightness and durability of the connection, while allowing for easy assembly and disassembly if necessary.

Couplings with a larger hexagon = universal application 

Couplings marked as "COUPLING/ADAPTER" are a special type of fittings and can also be used as straight adapters - this is because they have a larger hexagon for the wrench and thus have room for the use of a bonded seal (bonded washer), which will ensure a tight connection ( use as an adapter )  

Alternative designation for straight couplings 

Depending on the manufacturer, metric straight couplings may be named differently, hence they may appear under the names : Straight connector / Straight coupling; G Straight coupling / EO ends with 24° cone; Straight connector Type: Tn98; Straight coupling XG TN98; Reducing coupling XGR TN98R; Straight reducing connector / Straight reducing coupling; GR Straight reducing coupling; G Straight coupling

Technical parameters of straight couplings : 

• manufacturing standards: according to Polish Standard : PN-65/M-73141; according to DIN 2353
• execution : galvanized free-cutting steel or stainless steel 
• threads : male metric 
• cone with 24° seat
• purpose : connecting hoses or pipes 

Here is a description of the keyword straight thread prepared for SEO for the metric couplings category, including technical data and internal linking.

Straight thread in hydraulic couplings

In power hydraulics, a straight thread (also called a cylindrical or parallel thread) is a type of cut in which the outer and inner diameters remain constant throughout the length of the element. In contrast to tapered threads, a straight thread does not ensure tightness by simply jamming the threads, but requires the use of an additional sealing element.

Why is it worth using a metric straight thread?

In the assortment including metric straight couplings this solution is a standard in European systems. Its main advantages include:

• Ease of assembly: Possibility of multiple screwing and unscrewing without the risk of damaging the seat.

• Precise sealing: straight thread most often works with ED type sealing (elastomeric), O-ring or sealing on a 24° internal cone.

• High resistance: couplings made of free-cutting steel with white passivation guarantee safe operation even at high operating pressure.

Methods of sealing straight threads

When choosing hydraulic couplings, you should pay attention to the way a given straight thread will be sealed:

1. ED seal: the side screwed into the body (e.g. directional control valve or pump) has a rubber seal that is pressed against the flat surface of the seat.

2. Compression cone: The other side of the coupling usually has a cone on which self-sealing occurs after tightening the hose.

Photo gallery of metric straight couplings