Find Siemens S7-300 Parts — Including Obsolete and Discontinued Models
Looking for a Siemens S7-300 PLC, CPU, I/O module, communication module or power supply that is no longer available from Siemens?
S7Automation helps industrial customers source obsolete, discontinued and hard-to-find Siemens S7-300 automation components from our European inventory.
We supply new, new surplus and professionally refurbished Siemens S7-300 parts, backed by a 24-month warranty and technical support.
Need a specific Siemens part?
Search by Siemens part number
6ES7…
Can’t find your part number? Send it to our technical sales team and we’ll check our inventory and sourcing network.
Siemens S7-300 Obsolete Parts
The Siemens SIMATIC S7-300 remains installed in thousands of industrial automation systems around the world. Although many S7-300 components are no longer part of Siemens’ current product portfolio, replacing an entire PLC system is not always practical or necessary.
When a critical S7-300 component fails, finding the exact original part can be the fastest and most economical way to restore production.
S7Automation specializes in sourcing and supplying these hard-to-find components.
We can help you find:
- Siemens S7-300 CPUs
- Digital input modules
- Digital output modules
- Analog input modules
- Analog output modules
- SM signal modules
- CP communication processors
- IM interface modules
- Siemens S7-300 power supplies
- Profibus communication modules
- Ethernet / Profinet communication modules
- S7-300 mounting components
- Memory cards
- Front connectors
- Expansion modules
- Accessories and replacement components
S7-300 Parts Available in Different Conditions
Depending on the part number and availability, we can offer different purchasing options.
New
Original Siemens components in new condition, where available.
New Surplus
Genuine Siemens components sourced from surplus industrial inventory.
Professionally Refurbished
Used Siemens components that have been inspected and tested before shipment.
All eligible products are supplied with a 24-month warranty.
This allows you to choose the most appropriate solution based on your budget, urgency and application requirements.
Looking for a Siemens S7-300 Replacement?
If your original S7-300 component has failed, you may not need to replace the complete automation system.
Our technical team can help identify:
Original replacement
Find the exact Siemens part number whenever possible.
Refurbished replacement
A professionally tested original component can provide a cost-effective way to restore an existing installation.
Alternative component
Where appropriate, we can help identify an alternative or newer Siemens component.
Complete system upgrade
For older installations approaching the end of their operational life, we can also help you evaluate replacement options.
Send us your part number
If you have the Siemens part number, send it to us.
If you don’t know the part number, send us a photo, equipment description or information from the PLC cabinet.
Our technical sales team will help identify the required component.

Popular Siemens S7-300 Part Numbers
Our inventory includes a wide range of Siemens SIMATIC S7-300 components and related automation products.
Examples include:
- 6ES7 3xx
- 6ES7311
- 6ES7312
- 6ES7313
- 6ES7314
- 6ES7315
- 6ES7317
- 6ES7321
- 6ES7322
- 6ES7323
- 6ES7331
- 6ES7332
- 6ES7334
- 6ES7350
- 6ES7360
- 6ES7361
- 6ES7362
- 6ES7365
- 6ES7368
- 6ES7370
- 6ES7371
- 6ES7372
- 6ES7373
- 6ES7386
- 6GK7 communication modules
- Siemens S7-300 PS power supplies
- Siemens S7-300 CP communication processors
- Siemens S7-300 IM interface modules
Please search using the complete Siemens part number for the most accurate result.
Siemens S7-300 CPU Spare Parts
A failed CPU can bring an entire production line to a standstill.
S7Automation can help source Siemens S7-300 CPUs in different conditions, depending on current availability.
Typical S7-300 CPU families include:
CPU 312
Compact S7-300 CPUs for smaller automation applications.
CPU 313
S7-300 CPUs used in a variety of machine and process-control applications.
CPU 314
One of the widely used S7-300 CPU families.
CPU 315 / CPU 315-2 DP
Commonly installed in industrial automation systems requiring greater processing capability and Profibus communication.
CPU 317 / CPU 317-2 DP
Higher-performance S7-300 CPUs used in larger automation applications.
CPU 319
High-performance S7-300 CPU solutions for demanding applications.
Searching for a specific CPU?
Enter the complete Siemens part number into our search.
Why Buy Obsolete Siemens S7-300 Parts from S7Automation?
Large Siemens Inventory
Access a large inventory of Siemens industrial automation components through our European stock network.
Obsolete & Hard-to-Find Components
We specialize in helping customers source components that are difficult to obtain through normal distribution channels.
24-Month Warranty
Eligible products are supplied with a 24-month warranty, giving you additional protection when purchasing refurbished or obsolete equipment.
Tested Components
Our technical team can test suitable automation components before shipment, helping ensure that refurbished equipment is operational.
European Stock
Parts are supplied from our European inventory network, helping simplify international procurement and shipping.
Technical Support
Don’t know exactly which component you need?
Our technical sales team can help identify the required Siemens part and investigate replacement options.
Need an S7-300 Part Urgently?
Industrial automation failures don’t wait for standard purchasing cycles.
If a PLC component has failed and production is stopped, send us the Siemens part number and the required quantity.
We’ll check:
- Current stock
- Condition
- Available alternatives
- Warranty
- Shipping options
- Estimated delivery
Emergency S7-300 Spare Parts
Send us the part number → Check availability → Select the best condition → Ship from Europe
[ REQUEST AVAILABILITY ]
Siemens S7-300 Parts for Industrial Maintenance
S7-300 systems remain in operation across many industries, including:
- Manufacturing
- Oil & Gas
- Marine
- Energy
- Water & Wastewater
- Food & Beverage
- Chemical processing
- Automotive
- Packaging
- Building automation
- Process industries
- Machine manufacturing
For maintenance teams, keeping critical S7-300 spare parts available can significantly reduce the risk associated with unexpected component failure.
S7Automation can help you source critical spare PLC components before they are needed.
Don’t Replace an Entire PLC System Just Because One Component Failed
When an obsolete PLC component fails, a complete control-system migration can involve:
- Engineering costs
- New hardware
- Software changes
- Panel modifications
- Reprogramming
- Testing
- Commissioning
- Production downtime
For some installations, replacing the failed original component is a much faster and more economical solution.
S7Automation helps maintenance and engineering teams investigate the original-part replacement option first.
Can’t Find Your Siemens S7-300 Part?
Our online inventory contains many Siemens automation components, but not every available part is necessarily listed in the same way.
If your part number doesn’t appear in our search:
Send us the Siemens part number.
You can also send:
- A photograph of the label
- A photograph of the PLC module
- An old quotation
- A Siemens order number
- A description of the equipment
- The quantity required
Our team will investigate availability and contact you with the available options.
[ SEND PART NUMBER ]
Frequently Asked Questions
Is the Siemens S7-300 obsolete?
Many S7-300 components have been discontinued or phased out as Siemens has moved customers toward newer automation platforms. However, large numbers of S7-300 systems remain operational, creating continuing demand for spare and replacement components.
Can I still buy Siemens S7-300 CPUs?
Yes. Availability depends on the exact part number and condition. S7Automation supplies selected S7-300 CPUs and other components as new, surplus or refurbished products depending on stock.
Do you sell refurbished S7-300 modules?
Yes. Selected S7-300 modules can be supplied professionally refurbished and tested, subject to availability.
Do refurbished S7-300 parts have a warranty?
Eligible S7Automation products are supplied with a 24-month warranty.
Can you find a Siemens S7-300 part that is not listed on the website?
Yes. Send us the complete Siemens part number and our team can check additional inventory and sourcing options.
Can you identify an S7-300 module from a photograph?
In many cases, yes. Send a clear photograph showing the Siemens label and part number if possible.
Do you ship Siemens S7-300 parts internationally?
S7Automation serves customers internationally and can arrange shipping from its European stock network.
Should I replace my S7-300 with an S7-1500?
Not necessarily. The correct solution depends on the application, software, installed hardware, lifecycle requirements and downtime constraints. If you only need to replace a failed component, sourcing the original S7-300 part may be the fastest solution.
Find Your Siemens S7-300 Part Today
Whether you need a Siemens S7-300 CPU, I/O module, communication processor, power supply or another obsolete component, S7Automation can help you find the right part.
Search by part number.
Check stock.
Choose new, surplus or refurbished.
Get technical support.
Ship from Europe.
Search Siemens S7-300 Parts
Can’t Find Your Part?
Request a Quotation and we will be back to you within 4 hours
S7Automation — Siemens Automation Parts
Siemens PLCs • S7-300 • S7-400 • S7-1200 • S7-1500 • HMI • Drives • Industrial PCs • Obsolete Automation Parts
New • New Surplus • Refurbished
24-Month Warranty
European Stock • Worldwide Shipping
Technical Sales Reps available to guide you for a replacement part today

