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ISO-594-1 Fig 3a or 3b (ISO 80369-7) Ring Gauge for Male Luer Connector

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We offer Conical Ring Gages for the following specifications:
ISO 594-1 (DUO-Marked and DUO-Certified: ISO-594/ISO-80369-7)
ISO 80369-2 (soon to be offered)
ISO 80369-3
ISO 80369-6
ISO 80369-7 (not identical to ISO 594)

We also offer:
- DUO-Remarking/DUO-Recertification Service (ISO-80369-7 and ISO 594) for existing ISO 594 Gages and Reference Connectors


ISO 594 Has Been Replaced
ISO 80369-7 Foreword

ISO 80369-7:2016 cancels and replaces the first edition ISO 594-1:1986 and the second edition of ISO 594-2:1998, clauses, subclauses, tables, figures, and annexes of which have been consolidated and technically revised. The new ISO 80369-7 specification does not define any gauges.

We still offer the ISO 594 Conical Ring Gages
Understanding that some companies may desire to test select parts against the obsolete ISO 594 specification; we have continued to make available the ISO 594/1 conical gages.

ISO 594 Gages Can Be Used For ISO 80369-7 Connectors
The ISO 594-1 Gauges can be used to test ISO 80369-7 parts; however, in doing so you are giving up some of the ISO 80369-7 product tolerance. ISO 80369-7 Connectors which pass testing with ISO 594/1 conical gages will pass testing with gages designed for ISO 80369-7; however, connectors which pass testing with gages designed for ISO 80369-7 may fail testing when tested with ISO 594-1 conical gages. The authors of ISO 80369-7 have made slight changes to the Luer cones which slightly increased their size. The ISO 594 Luer cones fall within the sizes of the ISO 80369-7 cones so that they are completely backward compatible.
We Include DUO-Marking and DUO-Calibration
The ISO 594/1 Conical Gages we sell will be DUO-marked and DUO-calibrated; unless otherwise requested. We do this because they meet the ISO 594-1 gage design, and because ISO 80369-7 connections which are validated with the ISO 594/2 conical gages will meet the requirements of ISO 80369-7. We also understand that since ISO 80369-7 does not define conical gages, that leaves some flexibility in what could be considered the appropriate size for an ISO 80369-7 conical gage. We think that the ISO 594/1 conical gages are grandfathered into acceptance for testing ISO 80369-7 conical connectors, but for those who wish to move forward to the full size allowed by ISO 80369-7; we also offer gages designed to test the full size of ISO 80369-7 conical connectors; which are not backward compatible with ISO 594-1.
Can I Get My Existing ISO 594-1 Conical Gages DUO-Marked/DUO-Certiried?
Your existing ISO 594/1 Luer Gages may be sent to us. We will DUO-mark and DUO-certify the Luer Gauges and will return it to you. The certification will be by an ISO 17025 Accredited Calibration Laboratory which has Medical Gages and Reference Connectors in their ISO 17025 Scope. The cost of this service to you varies depending on how many gages are processed at one time. The DUO-mark and DUO-certify process will take about 4 weeks to complete.
Which ISO 594 gage do I need: 3a or 3b?
Both ISO 594/1 and ISO 594/2 have the same Luer 6%-taper male conical fitting. ISO 594/1 identifies the requirements of the Luer 6%-taper male conical fitting for both standards. ISO 594/2 adds a permanently connected internally threaded collar. ISO 594/1 defines the gages to test the Luer 6%-taper male conical surface for both ISO 594/1 and ISO 594/2. ISO 594/1 offers two confiturations of the Conical Ring Gages: Figure 3a and Figure 3b.
How do I choose between ISO 594/1 Fig 3a and ISO 594/1 Fig 3b Ring Gages?
The difference between ISO 594/1 Fig 3a and Fig 3b is that ISO 594/1 specifies Fig 3a for Rigid materials and Fig 3b for Semi-Rigid materials. If your material is Rigid or Semi-Rigid is a decision which must be made locally because ISO 594/1 does not narrowly define the distinction.
ISO 594/1:1996; Page 1; Paragraph 1 NOTE states:
It is not practicable to define the characteristics of rigid or semi-rigid materials with precision, but glass and metal may be considered as typical rigid materials. By contrast, many plastic materials may be regarded as semi-rigid although the wall thickness is an important factor influencing the rigidity of a component.
So the decision is yours. If you consider your part to be Rigid Material; use ISO 594/1 Fig 3a. If you consider your part to be Semi-Rigid Material; use ISO 594/1 Fig 3b. In ISO 80369-7 there is no distinction between Rigid and Semi-Rigid materials; so if you do not wish to distinguish between Rigid and Semi-Rigid; then pick the Fig 3b gage which tests the full size of the ISO 80369-7 Male Luer Conical Connector.
More Decisions to make: Ring with C'Bore; Ring with Handle; or 5-Newton Weighted Ring?
Testing the Luer-Slip male conical fitting of ISO 594/1 is easier than testing the Lure-Lock male conical fitting of ISO 594/2.  The Lure-Lock male conical fitting of ISO 594/2 has a threaded lock collar surrounding the male conical fitting which inhibits the application of a ring gage. Medi-Luer offers solutions to this problem of clearing the ISO 594/2 Threaded Lock Collar.

ISO80369-7 Ring Gage Image
The advantages and disadvantages of the Ring with C'Bore

The Medi-Luer ISO 594/1 Figure 3a and 3b Ring Gages have a counter-bore designed to clear MOST ISO 594/2 threaded collars. Be sure to check your ISO 594/2 collar design before using the ISO 594/1 Figure 3a or 3b Ring Gage because the counter-bore is 15.87mm (0.625”) minimum diameter by 4.7mm (0.185”) minimum deep. Following the design specifications of ISO 594/2, some collars may have a collar outside diameter configuration or a length which will interfere with the function of the gage. Careful reading of ISO 594/2 will reveal that ISO 594/2 does not specify an outside diameter for the collar and reading plus a little math will reveal that the collar may be as tall as 5.4mm (2.126”).

I know; why not just make the counterbore deeper? The thin wall at the bottom of the counterbore is a high scrap point in the gage manufacturing process and to solve that problem it had to be a little thicker. What has resulted is the ISO 594/1 Figure 3a or 3b Ring Gage which works in MOST instances. In those instances where it will not work we have the ISO 594/1 Figure 3a or 3b Ring Gage with Handle.

NOTE: Some end user companies successfully have taken it on themselves to machine the counterbore deeper. This action will void the manufacturer’s warrantee.

The advantages and disadvantages of the Ring Gage with Handle
The ISO 594/1 Figure 3a or 3b Ring Gage with Handle will completely clear the ISO 594/2 collar in all cases. Basically the ring gage is manufactured as a thin wall tube, notched at the appropriate places and inserted in a handle. There two disadvantages to the ISO 594/1 Figure 3a or 3b Ring Gage with Handle: a) The cost is higher because of the increased difficulty in manufacturing. b) Because it is hardened stainless steel thin wall tube with a notch cut out of it, it is more easily damaged while it is being used.
Image of 5-Newton Weighted Ring Gage
The advantages and disadvantages of the 5-Newton Weighted Ring Gage

The 5-Newton Weighted Ring Gage is the Ring Gage with Handle with added weight so that the ISO 594 specified application force of 5-Newtons is met with just the application of the gage. The 5-Newton Weighted Ring Gage will completely clear the ISO 594/2 collar in all cases.
With Or Without 5 Newton Weight?
This is an internal decision for you to make.
We recommend with the 5 Newton weight because:
1. ISO 594/1 demands that the Luer Gauge be applied to the part with a force of 5 Newtons.
2. Application of the 5 Newton force is an inaccurate cumbersome operation if the 5 Newton weight is not integral to the Luer Plug Gage.
3. The test results can easily be falsified or skewed depending on how much unregulated force is applied to the Luer Plug Gauge.
If you desire repeatable results from the Luer Plug Gage, then select the Luer Plug Gauge with the 5 Newton weight.
Follow this link if you wish a more in-depth discussion on the 5 Newton force.


The following data is extracted from ISO 594/1 and expanded for further clarification.

5.1 Gauging Test: The procedure shall be carried out as specified below in 5.1.1 to 5.1.4.

5.1.1 Carry out the test using steel gauges as illustrated in ISO 594/1 Figure 3.

5.1.2 Carry out the test at a temperature of 20°C +/-5°C.

5.1.3 Prior to testing, condition products made from hygroscopic materials at 20°C +/-5°C and 50% +/-10% relative humidity for not less than 24 hours. Conditioning is not required for products made from non-hygroscopic materials.

5.1.4 Apply the gauge to the conical fitting with a total axial force of 5 Newtons, without the use of torque. Remove the axial load.

4.1.1 Gauging test results:

a. The small end of the male conical fitting shall lie between the two limit planes of the gauge.

b. The larger end of the tapered portion shall extend beyond the datum plane of the gauge.

c. Rocking shall not be evident between the gauge and rigid material fitting undergoing test. This test for freedom from rocking may also be found useful (not required) for evaluating semi-rigid fittings.[Editorial note: The rocking MAY indicate interference between the collar and the gage.]


How to Apply 5 Newton Force
I cannot make this decision for you, but I will supply you with some thoughts about this topic for discussion. What ever you decide you need to support logically to whomever requests your reasoning for your method.

The 5 Newton weight (approximately 18 ounces/510 grams) could be considered a 'light' weight. Neither ISO 594/1 nor ISO 594/2 apply a tolerance to the 5N force. Since there is no tolerance defined; we have considered the 5 Newton force as a nominal value and have applied a conservative tolerance to that. We have converted the 5 Newton force to grams; we use 509.86 grams +/- 0.75 grams.

What is a conservative Tolerance?
There is a 10% Tolerance Rule common in industry which basically uses 10% of the product specification as the tolerance. If we apply 10% of the 5 Newton weight as tolerance (5N+/-0.25N) we should have a conservative tolerance. There are many variables in the application of the 5-Newton force which can be controlled, but are illogical to control because of the expense involved in maintaining that control compared to the benefit of such stringent control. If this is the direction you wish to travel in using the ISO 80369-7 (ISO 594/1 Fig 3a or 3c) Luer Ring Gage; we offer it with 5-Newton total weight.

Do I Need The Gages Marked For ISO 80369-7?
That depends on your internal procedures.

- If your quality assurance environment is flexible enough for you to make an internal informal adoption of the obsolete ISO 594/1 Gauges for testing ISO 80369-7 Luer Connectors; your existing gauge will work just fine until it wears out. When it needs to be replaced be sure to get the replacement gage DUO-Marked for both ISO 80369-7 and ISO 594/1. The gages we sell will automatically be DUO-Marked.

- If your quality assurance environment is more restricted and cannot accept the use of a gauge which is not marked or certified to the appropriate specification; we suggest DUO-marking and DUO-certifying the existing Luer Gage to both the requirements of ISO 594 and ISO 80369-7. This DUO status is accurate to both the specifications and will allow you to use the Luer Gauge in either application in your business. We offer the DUO-marking/certifying service.

If your quality assurance environment has no flexibility; then buy a new ISO 80369-7 Luer Ring or Plug Gage. Be aware that we are DUO-marking and DUO-certifying our new Luer Gauges, so if you wish an ISO 80369-7 Luer Ring or Plug Gage marked only for ISO 80369-7 or only ISO 594/1; that may be a special request.


We Offer DUO-Marking and DUO-Calibration
We offer DUO-marking and DUO-calibration in two ways:
1 - New Luer Gauges will be DUO-marked and DUO-certified; unless otherwise requested.
2 - Existing Luer Gage may be sent to us. We will DUO-mark and DUO-certify the Luer Gauge and will return it to you. The certification will be by an ISO 17025 Accredited Calibration Laboratory which has Medical Gages and Reference Connectors in their ISO 17025 Scope. The cost of this service to you varies depending on how many gages are processed at one time. The DUO-mark and DUO-certify process will take about 4 weeks to complete.

General Construction Data:
The conical ring gage test product contact portions are made of Stainless Steel and hardened to Rockwell C-scale: 56 to 58; the weight is made of Stainless Steel without hardening. The use of hardened steel for gage working surfaces is is not a requirement of any specification; however, we consider it best-practice to use hardened materials for gages so that you have the most reliable inspection tool. If you must have this data certified; this is considered a special request. There will be an extra cost and the lead-time for the gage may double.

This data is provided for general information only. The intention is to provide accurate information; regardless; errors may exist in the supplied information. If accuracy is critical, base your final decisions on the data provided in the root documents: ISO594/1:1986; ISO 594/2:1998, ISO80369-7:2016, and ISO80369-20:2014; which are copyrighted documents. 
To purchase copies visit an Authorized Reseller.

Original Posting: 1/11/2008
Last Revision: 3/5/2018
Error corrections in, or comments about, the above data can be sent to: office@gagecrib.com


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Gage Crib Worldwide, Inc.
6701 Old 28th St SE, Suite B
Grand Rapids, MI 49546-6937
Phone: 001-616-954-6581 • Fax: 001-616-954-6583

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