I was trying to find out opinion of a famous value/defensive stock investor Benjamin Graham on maximum acceptable values P/E, P/B, Debt/Equity when considering buying a stock. This is what I have found. Feedback is needed:

"Graham recommended a P/E ratio no higher than 13.3 based on an AA Bond Yield of 7.5%."
"defensive investor in the U.S. today could consider stocks with P/E ratios up to 30, since 10-year AA Corporate Bond Yields are now close to 3.3%."
-> https://ycharts.com/indicators/us_co...ffective_yield currently shows "long term average of 4.10%". When i divide 100/4.1=24. So currently i should not buy stock with P/E above 24 per my understanding.

"Graham's maximum investable thresholds for these ratios were 15 for P/E and 1.5 for P/B. However, he was willing to accept a higher P/B ratio when the P/E was low. So he would also look at the P/E ratio multiplied by the P/B ratio -- targeting a maximum value of 22.5."
"Graham is a believer in using a low price-to-book-value ratio to select stocks and normally requires a ratio below 1.5 for the defensive investor."

"He specified that debt should not exceed twice the stock equity (at book value, not market value)." https://seekingalpha.com/article/449...alue-investing
-> It implies that the debt/equity ratio (shown by Morningstar/Valuation for example) should not be higher than 2.0. If the ratio exceeds 2.0, it suggests that the company has higher financial leverage and a potentially higher risk associated with its debt levels.

P/E < 15 (other source calculate < 24)
P/B < 1.5 (Confirmed from 2 sources. Higher value is acceptable in case P/E was low: multiply P/E and P/B and ideal is if the result is < 22.5 or < 36 in case we use P/E value 24 above))
Debt/equity < 2.0 (2.0 means that the company has 2x higher debt than its equity)

I am unsure about correctness of any values, especially 22.5 one in the light of possible need to calculate the acceptable P/E based on current "10-year AA Corporate Bond" as quoted.