Views: 0 Author: Kevin Fang Publish Time: 2026-08-26 Origin: Chensheng Medical
Table of Contents
Selecting medical silicone tubing is not simply a matter of choosing an inside diameter and placing an order. For medical device manufacturers, pharmaceutical equipment builders, and healthcare product developers, tubing specifications directly affect fluid flow, connection security, pump performance, sterilization compatibility, patient safety, and regulatory documentation.
A tube that appears correct on a basic drawing may still fail in assembly if its wall thickness varies too much, its hardness is not suitable for the fitting, or its dimensions change after sterilization. A complete specification helps prevent those risks before tooling, sampling, and mass production begin.
This guide explains what to include when specifying medical grade silicone tubing for a custom OEM or ODM project.
Specify ID, OD, wall thickness, length, and tolerances separately; do not rely on a general “standard tolerance” statement.
The right tubing design depends on the application’s fluid, pressure, vacuum, temperature, bending, pump, and sterilization requirements.
Material grade, Shore A hardness, color, cleanliness, and documentation should be defined early in the development process.
For critical medical fluid paths, dimensional inspection alone is not enough; consider leakage, pull-off, kink, burst, and sterilization validation as applicable.
Sending a complete RFQ package to your supplier reduces sampling iterations, tooling changes, and production delays.
Before defining dimensions, clarify what the silicone tubing must do in the final device or system.
Medical silicone tubing is commonly used in:
IV infusion and drug-delivery devices
Peristaltic pump systems
Respiratory circuits and ventilator accessories
Catheters and drainage assemblies
Dialysis and fluid-management systems
Pharmaceutical processing and fill-finish equipment
Laboratory analyzers and diagnostic instruments
Surgical suction and wound drainage systems
The same tubing dimensions can perform very differently depending on whether the tube transports saline, air, blood, a drug formulation, or process fluid. The correct design should account for the complete operating environment—not only the drawing.
What fluid, gas, or media will contact the tubing?
Is the tube part of a patient-contacting device, a pharmaceutical process, or laboratory equipment?
What are the normal and maximum operating pressure conditions?
Will the tube experience vacuum, repeated compression, bending, or clamping?
Is it connected to a barb fitting, luer component, molded connector, pump head, or other assembly?
What sterilization method will be used?
What regulatory, biocompatibility, or customer documentation is required?
Is this a prototype, pilot run, or long-term mass-production program?
Providing these answers allows the supplier to evaluate manufacturability and recommend an appropriate material and production route.
The three fundamental dimensions of silicone tubing are:
ID — Inside Diameter
OD — Outside Diameter
Wall Thickness
The relationship is:
For example, a tube with a 3.0 mm ID and 5.0 mm OD has a nominal wall thickness of:
However, nominal dimensions are only the beginning. A medical tubing drawing should also define acceptable variation and the dimensions that are most critical to device performance.
The ID typically has the strongest influence on:
Fluid flow rate
Pressure drop
Compatibility with internal components
Pumping performance
Catheter or guidewire passage, where applicable
Retained fluid volume
If a tube is used in a fluid path, the ID should be selected according to the intended flow requirement, viscosity of the fluid, tubing length, and allowable pressure loss.
The OD is particularly important for:
Fit with external connectors or housings
Routing through device channels
Clamp compatibility
Tube retention features
Overall device size and ergonomics
Wall thickness affects more than tubing strength. It can influence:
Resistance to kinking and collapse
Flexibility and bend radius
Burst-pressure performance
Vacuum resistance
Compression behavior in pump applications
Connector engagement and pull-off performance
A thinner wall may improve flexibility, but it can reduce resistance to collapse or increase variation risk. A thicker wall may improve robustness, but it can make assembly more difficult or affect pumping behavior.
One of the most common problems in custom silicone tubing sourcing is an incomplete tolerance callout.
Avoid specifying only:
“Medical silicone tube, 3 × 5 mm, standard tolerance.”
This leaves too much room for interpretation. Instead, specify the tolerance for each dimension that affects function.
Specification Item | Why It Matters |
Inside diameter tolerance | Affects flow, fit, and internal component passage |
Outside diameter tolerance | Affects connectors, clips, device routing, and housings |
Wall thickness tolerance | Affects flexibility, pressure resistance, and collapse resistance |
Length tolerance | Important for cut pieces, kits, and automated assembly |
Ovality | Important when sealing, pumping, or connecting to precision fittings |
Concentricity | Helps ensure consistent wall thickness around the tube |
Straightness | Relevant for assembly, packaging, and automated processing |
Surface quality | Important for visual inspection, cleanliness, and assembly |
Achievable tolerance depends on multiple variables:
Tube size and wall thickness
Material formulation and Shore hardness
Extrusion process stability
Whether the tubing is supplied in coils or cut lengths
Required post-processing
Inspection method
Functional risk of the application
For critical device applications, it is better to identify critical-to-quality dimensions on the drawing. A supplier can then focus process control and inspection resources on the features that affect your assembly or clinical performance.
Silicone hardness is generally measured on the Shore A scale. In medical silicone tubing, hardness influences flexibility, resilience, assembly force, sealing behavior, and fatigue performance.
Hardness Range | Typical Characteristics | Common Considerations |
Lower Shore A | Softer, more flexible, easier to bend | May require additional design attention for kink or collapse resistance |
Medium Shore A | Balanced flexibility and mechanical strength | Suitable for many general medical tubing and fluid-transfer applications |
Higher Shore A | More rigid, stronger shape retention | May be beneficial for handling and pressure resistance, but can increase assembly force |
The correct hardness should be selected based on the actual application rather than a generic preference for “soft” or “hard” silicone.
For example:
A peristaltic pump tube may need consistent elastic recovery and fatigue resistance.
A drainage tube may require a balance of patient comfort, flexibility, and kink resistance.
A connector-mounted tube may require sufficient strength to resist pull-off or leakage.
A respiratory circuit component may need softness, transparency, and resistance to repeated handling.
When in doubt, ask the supplier to review the tubing with the mating connector, pump head, or complete assembly conditions.
A tube that works in a static sample test may fail during actual use if it is repeatedly bent, clamped, pressurized, or exposed to vacuum.
Burst-pressure resistance
Leakage resistance
Vacuum-collapse resistance
Kink resistance
Tensile strength and elongation
Tear resistance
Compression set
Repeated flex fatigue
Peristaltic pump life
Pull-off force from connectors
Kinking is especially important in drainage, infusion, respiratory, and wearable medical devices. It may reduce or stop fluid or gas flow.
Kink resistance is influenced by:
ID-to-wall-thickness ratio
Material hardness
Tube routing and bend radius
Operating temperature
Reinforcement design, if required
Connector location and assembly stress
If the tubing will bend tightly in the finished device, provide the supplier with the intended routing path, minimum bend radius, and any expected clamping points. This helps identify whether a standard extrusion is appropriate or whether a design adjustment is needed.
“Medical grade silicone” is not a complete technical specification by itself. Buyers should define the intended application, required documentation, and applicable standards.
Depending on the project, requirements may include:
Medical-grade silicone raw material
USP Class VI material test information, where applicable
ISO 10993 biological evaluation support for the finished device
FDA-related material compliance documentation, where applicable
Latex-free declaration
RoHS and REACH declarations for markets where they are relevant
Batch traceability
Certificate of Analysis or Certificate of Conformance
Material lot information
Change-control notification requirements
It is important to distinguish between material-level information and finished-device compliance.
For example, a silicone raw material may have supporting test data, but the final medical device still requires evaluation based on its intended use, patient-contact category, contact duration, sterilization method, processing conditions, and applicable market regulations.
For pharmaceutical fluid-path applications, material extractables and leachables may also be a central part of supplier qualification. See our related guide: Silicone Tubing for Pharmaceutical Manufacturing: Extractables, Leachables, and Regulatory Compliance.
Medical silicone tubing can be transparent, translucent, or colored depending on functional and identification needs.
This is often preferred when users need to observe:
Fluid movement
Air bubbles
Particulates
Blockages
Color changes in fluids
Color can support:
Product identification
Line differentiation
Assembly error prevention
Brand-specific design requirements
If color is required, specify the color standard whenever possible, such as a physical sample, Pantone reference, or approved color chip. The specification should also clarify whether color consistency must be controlled across lots.
The desired surface condition should be included if it affects use or assembly. Consider:
Smoothness
Tackiness
Parting lines or extrusion marks
Particulate control
Visual inspection requirements
Compatibility with printing, marking, or bonding
Sterilization may affect silicone tubing appearance, physical properties, packaging, or mating components. The final sterilization method should be considered during product development—not after mass production begins.
Common methods include:
Ethylene oxide (EtO)
Steam autoclave sterilization
Gamma irradiation
Electron beam sterilization
The actual effect depends on the silicone formulation, tubing geometry, additives, packaging configuration, sterilization cycle, and performance requirements.
For a critical application, validate the finished component or finished device after the intended sterilization cycle. Relevant checks may include:
Visual appearance
Color change
Dimensional stability
Hardness
Tensile properties
Leakage performance
Odor or residual concerns
Package integrity
Do not assume that a silicone tube suitable for one sterilization process will automatically be suitable for all sterilization methods.
Medical silicone tubing is commonly manufactured by extrusion. However, some applications require molded ends, integrated connectors, valves, seals, or more complex geometries.
Depending on the component design, an OEM supplier may recommend:
Silicone extrusion for continuous tubing
Cut-to-length tubing
Extrusion with post-curing
Liquid silicone rubber injection molding
Compression molding
Overmolding or insert molding
Secondary assembly with plastic or metal components
For a detailed comparison, read: Medical Silicone Extrusion vs. Injection Molding vs. Compression Molding: Which Process Is Right for Your Component?.
In general, process selection should be based on geometry, annual volume, tolerance needs, assembly requirements, tooling cost, and validation strategy—not solely on piece price.
Documentation requirements vary by project, but qualified medical device buyers commonly request some combination of the following.
Document or Record | Purpose |
Product specification or approved drawing | Defines dimensions, materials, and acceptance criteria |
Certificate of Conformance | Confirms supplied product meets agreed requirements |
Certificate of Analysis, where applicable | Provides material or batch test information |
Material declaration | Identifies the silicone material system used |
Batch or lot traceability record | Links finished product to production and material lots |
Inspection report | Documents dimensional, visual, or functional checks |
Quality-system certificate | Supports supplier qualification, such as ISO 13485 certification where applicable |
Change-control procedure | Defines how material, process, tooling, or facility changes are communicated |
Packaging specification | Defines packaging configuration and cleanliness controls |
Sterilization or biocompatibility support documents | Provided as applicable to the scope of supply and project requirements |
The document package should be agreed before production approval. This avoids a common purchasing problem: receiving acceptable physical parts but insufficient records for incoming inspection, supplier qualification, or regulatory files.
To receive an accurate quotation and practical engineering feedback, provide as much of the following information as possible.
2D drawing, 3D model, reference sample, or written dimensions
Tube ID, OD, wall thickness, and length
Dimensional tolerances
Required Shore A hardness
Color and transparency requirements
Application and fluid-contact details
Operating pressure, vacuum, temperature, and bend requirements
Sterilization method, if known
Required tests or acceptance criteria
Required compliance and quality documentation
Packaging requirements
Prototype, annual, and forecast quantities
Required sample and mass-production timing
Mating connector or assembly details, if available
If drawings are not yet complete, an experienced supplier can often support early-stage manufacturability review based on a sample, application description, and preliminary dimensions.
Jinan Chensheng Medical Technology Co., Ltd. provides OEM and ODM support for medical-grade silicone tubing, catheters, molded silicone components, and related medical fluid-management products.
For custom projects, our team can support customers from early specification review through sampling and mass production, including:
Medical silicone tubing dimension and material evaluation
Custom extrusion and cut-to-length processing
Mold development and molded silicone components
OEM/ODM project support
Manufacturing-process recommendations
Quality documentation and traceability support
Communication for overseas sourcing and remote supplier evaluation
Whether you have a complete engineering drawing or only an initial concept, providing your functional requirements early helps create a more reliable and cost-effective tubing solution.
Looking for a medical silicone tubing manufacturer for an OEM or ODM project?
Send us your drawing, sample, tubing dimensions, target quantity, application, and documentation requirements. Our team will review the project and recommend an appropriate manufacturing approach.
Contact Chensheng to discuss your custom medical-grade silicone tubing project.
At minimum, provide the ID, OD, wall thickness, length, hardness, color, quantity, and intended application. For a more accurate quotation, also include tolerances, sterilization method, connector details, packaging, required documentation, and a drawing or physical sample.
ID tolerance controls the internal fluid path and internal fit. OD tolerance controls external connector fit, device routing, clamps, and housing interfaces. Both should be specified independently when they are critical to product function.
Yes. Custom silicone tubing can be developed in different IDs, ODs, wall thicknesses, lengths, hardness levels, colors, and packaging formats. Final feasibility depends on the geometry, tolerance requirements, material selection, and production volume.
Choose hardness based on the tube’s function. Consider flexibility, anti-kink performance, pressure or vacuum resistance, pumping behavior, connector fit, patient-contact requirements, and sterilization conditions. Testing the tubing in the final assembly is recommended for critical applications.
Yes, silicone tubing is widely used in peristaltic pumping applications. However, pump-head geometry, compression level, operating speed, fluid, temperature, and required service life should be evaluated to select the right dimensions and material properties.
No. USP Class VI and ISO 10993 are different frameworks. USP Class VI is commonly associated with material testing, while ISO 10993 addresses biological evaluation of medical devices based on their intended use and patient-contact conditions. The final device manufacturer remains responsible for the appropriate finished-device evaluation.
Silicone tubing may be compatible with EtO, steam, gamma, or e-beam sterilization, depending on the material, design, packaging, and validated process. Compatibility should be confirmed for the final component or device under the actual sterilization conditions.
Lead time depends on tubing complexity, material availability, whether tooling is required, testing requirements, sample revisions, order quantity, and packaging needs. Share your target schedule during the RFQ stage so the supplier can assess feasibility and plan accordingly.
