Advanced Core Wire Technology Enabling Next-Gen Guidewire and Delivery Systems

By Chamfr Team

June 30, 2025

In this sponsored technical blog post, Wytech explores the critical role core wire design plays in the performance of guidewires and delivery systems used across interventional and minimally invasive procedures. Drawing on 50 years of grinding and medical wire expertise, Wytech shares how its FastTrack program helps engineers accelerate development with precision-tapered components, rapid lead times, and hands-on design support.

Introduction

The invention of the “guidewire” by Dr. Forssmann in 1929 is a story of a vision and boldness that has impacted modern medical practices and laid the foundation for minimally invasive surgical procedures ranging from cardiology, coronary, peripheral vascular, neurovascular, and neurology.  The guidewire evolution through the decades was accelerated by micro-wire manufacturing in the 1980’s-2000’s and still advances today.

What Role Does the Core Wire Play

As presented in the paper “Basics of Guidewire Technology and Peripheral Artery Disease” ¹, there are four design elements to a guidewire that can also apply to a wire based deployment system.

1. Core Wire
2. Coils/Cover
3. Coating
4. Tip Design

Image Source: Srini Tummala 1,✉, Mike Patel 1 ,“Basics of Guidewire Technology and Peripheral Artery Disease”, National Library of Medicine, 2023

The four common functional attributes of a guidewire or delivery system that are influenced by the design are:

1. Pushability (Strength/Rigidity)
2. Flexibility (at Distal Tip)
3. Kink Resistance
4. Torque Ability

The development and design of the core wire has a direct impact to the overall guidewire ability to bend around a tortuous path or push through a calcified lesion in the vasculature.

The core wire performance in a delivery system will also impact the device’s ability to deliver torque at the distal end and delivery the therapy whether that is to present drugs, an implant, rotating instruments, or diagnostics to the targeted anatomy area.

Do Standards of Core Wire Design Exist?  

There are general standards for core wire elements, but every wire design is uniquely evaluated and optimized for performance to its respective clinical therapy. The four variables that impact the above functional characteristics of a core wire are:

• Material
• Coatings
• Diameter
• Taper Design

1. Metal Material Options:

Three traditional metal alloys have dominated the core wire landscape over the last 30 years.

• Stainless Steel: 304, 304V, 316LVM, SLT® Sprint Temper, SLT® Hyten Type 4
• Nitinol flexibility/shaping): Superelastic Nitinol light and dark oxide
• Specialty Alloys (stiffness): Tungsten, Cobalt Chrome alloys

Material selection has an impact on functional performance. For optimal pushability (strength/rigidity) a cobalt chrome material or a Hyten® Stainless Steel core wire is the best option. For kink resistance, nitinol is the best choice.

SLT® is a registered trademark product of Fort Wayne Metals, Fort Wayne, Indiana

2. Coating Material Options: 

The ability of the core-wire and guidewire assembly to push through tortuous vasculature or lesions, can be improved upon with a lubricious coating.  Two of the common coatings are PTFE and Hydrophilic.

PTFE Coatings: This coating is applied to the metal wire one of two ways:

1. Coating dispersion process which has full coverage over the outside diameter of the wire and applied with a single or multiple passes through a PTFE resin reservoir.  This coating can be selectively removed mechanically or via a laser, to expose bare metal beneath.  
2. Coating electro-static spray process, has the ability to selectively coat areas of the wire and using shadow or tape masking to retain bare metal in uncoated areas.

Hydrophilic Coatings: Coating is applied to metal wire or on top of polymers most commonly through a dip method.

1. Dip-Coat / Drain-Cure Process – The wire is first cleaned and micro-etched (solvent wash, acid, or plasma) to promote adhesion, then immersed in a hydrophilic-polymer dispersion. Controlled withdrawal, drainage, and either thermal or UV curing lock the polymer network around the full circumference. Multiple passes can be used to build thickness. 

3. Common Wire Starting Diameters:

Guidewire design, much like catheters, have standardized around common French size, and in the case for cardiovascular, neurovascular, and urology based applications, common diameters are 0.014”, 0.018”, 0.035”.and 0.038”.  With wire based deployment systems the starting diameters are much more specific to the implant or therapy that is being delivered and can range from 0.008” to greater than 0.100”. 

The most common diameters of 304 Stainless Steel and Nitinol core wires are available for 24-hour shipment from Wytech on Chamfr, making it easier to quickly source what you need for R&D.

4. Taper Design:

Predicate guidewire or delivery system designs are often used to benchmark the taper design. While clinicians using legacy devices have mastered guidewire performance based on years of training and technique, it should be noted that some of the most successful workhorse or platform-based guidewire products have been in existence for over 25 years. Legacy guidewire platforms were shaped by the manufacturing capabilities of their time. With modern centerless grinding technologies, design engineers can now achieve tighter tolerances, smoother transitions, and more complex geometries, enabling next-generation performance without design compromises of the past. While predicate designs are a good starting point to baseline, it is recommended that design engineers bring in manufacturing experts to support the clinical design intent. 

Common evaluation techniques include tests for tractability testing, rotation evaluation for torque-ability, and insertion force test, all of which are dependent on the clinical anatomy that is being targeted by the engineer.

Refining Tapered Profiles in the Development Cycle

Wytech’s FastTrack core wire technical team is passionate about collaborating with our customers whose products span across interventional and minimally invasive surgical markets. Our technical team will work diligently to identify and understand your ground catheter mandrel or core wire design, to deliver custom medical wires that meet your application performance needs.

The following is a reference summary of the common tapered features, core wire materials, and tolerance that can be provided.

Who Should Consider Using FastTrack?

FastTrack is ideal for R&D teams, design engineers, and catheter developers building complex systems for:

Access to Subject Matter Experts coupled with fast lead times gives your team more time to iterate, test, and refine—helping you meet aggressive development timelines without compromising on component quality. FastTrack also minimizes friction between design intent and manufacturability by bridging to qualification and full volume production.

How FastTrack Works (3 Options to Suit Every Need)

1. Discrete (one-time) Quote and Purchase Order: Customer sends in a quote request (drawing or napkin) and FastTrack team quotes in 48 hours.  Lead time 2-4 weeks.
2. Reoccurring Development Quote/Blanket Purchase Order: Customer communicates need for development with several ground wire iterations between evaluation and testing periods. Blanket PO Releases triggered from email requests. Lead time 1-2 weeks.
3. On-Site Development: Customer wants to rent out staff and equipment at a daily rate to iterate prototyping and testing in real-time. Daily/weekly rental rates are available via request.

Design Success, Partner Understanding, Communication and Reliability
Start Fast. Stay Precise.

With 50 years of medical wire and precision grinding expertise, Wytech understands what it takes to move quickly and get it right. FastTrack is backed by the same organization that produces over 87 million precision components annually—so when it’s time to scale, you’re already in the right place.

Contact our technical team to submit a drawing and get your DFM review started.

Meet Bobby | FastTrack Business Unit Manager

With 30+ years of hands on precision grinding experience, Bobby leads Wytech’s FastTrack Rapid Prototyping program. He specializes in grinding tight-tolerance wire and mandrel components used across a wide range of interventional and minimally invasive medical devices—from structural heart and neurovascular systems to electrophysiology and peripheral applications.

Bobby’s team has the ability to achieve complex geometries, micro features, and consistent performance at prototype volumes making FastTrack a trusted resource for engineers pushing the limits of design.

Meet Jen | FastTrack Inside Sales Manager

With nearly two decades of experience at Wytech, Jen brings a strong customer-first mindset to our FastTrack Rapid Prototyping program. Starting in 2005, Jen’s journey through customer service and estimating has shaped her into a trusted partner for engineers and purchasing teams alike.

Today, Jen applies that experience to help accelerate development timelines and ensure projects run smoothly from quote to production.

Get Started with FastTrack Prototyping

Complete this form and the FastTrack Prototyping team will contact you to discuss your project.

About the Supplier

Wytech is a trusted outsourcing partner for medical wire and metal tubing components leveraging precision grinding and machining capabilities. Wytech offer stainless steel, nitinol, PTFE-coated, and parylene-coated wires and mandrels, ready to ship within 24 hours. From precision ground and machined catheter mandrels to core wires, Wytech supports projects from prototyping to high-volume production, helping accelerate R&D efforts. Explore Wytech’s in-stock components to begin your custom ground mandrel or core wire project – or contact our technical team to get started on your custom designs and rapid prototyping.

_{Srini Tummala ^1,✉, Mike Patel ¹  ,“Basics of Guidewire Technology and Peripheral Artery Disease”, National Library of Medicine, 2023}